exploits

Ransomware attackers quickly weaponize PHP vulnerability with 9.8 severity rating

Biz & IT, exploits, php, ransomware, Security, vulnerability / Ryan Harris / June 14, 2024

FILES LOCKED —

TellYouThePass group opportunistically infects servers that have yet to update.

Dan Goodin – Jun 14, 2024 7: 40 pm UTC

Photograph depicts a security scanner extracting virus from a string of binary code. Hand with the word — Getty Images

Ransomware criminals have quickly weaponized an easy-to-exploit vulnerability in the PHP programming language that executes malicious code on web servers, security researchers said.

As of Thursday, Internet scans performed by security firm Censys had detected 1,000 servers infected by a ransomware strain known as TellYouThePass, down from 1,800 detected on Monday. The servers, primarily located in China, no longer display their usual content; instead, many list the site’s file directory, which shows all files have been given a .locked extension, indicating they have been encrypted. An accompanying ransom note demands roughly $6,500 in exchange for the decryption key.

Enlarge / The output of PHP servers infected by TellYouThePass ransomware.

Censys

Enlarge / The accompanying ransom note.

Censys

When opportunity knocks

The vulnerability, tracked as CVE-2024-4577 and carrying a severity rating of 9.8 out of 10, stems from errors in the way PHP converts Unicode characters into ASCII. A feature built into Windows known as Best Fit allows attackers to use a technique known as argument injection to convert user-supplied input into characters that pass malicious commands to the main PHP application. Exploits allow attackers to bypass CVE-2012-1823, a critical code execution vulnerability patched in PHP in 2012.

CVE-2024-4577 affects PHP only when it runs in a mode known as CGI, in which a web server parses HTTP requests and passes them to a PHP script for processing. Even when PHP isn’t set to CGI mode, however, the vulnerability may still be exploitable when PHP executables such as php.exe and php-cgi.exe are in directories that are accessible by the web server. This configuration is extremely rare, with the exception of the XAMPP platform, which uses it by default. An additional requirement appears to be that the Windows locale—used to personalize the OS to the local language of the user—must be set to either Chinese or Japanese.

The critical vulnerability was published on June 6, along with a security patch. Within 24 hours, threat actors were exploiting it to install TellYouThePass, researchers from security firm Imperva reported Monday. The exploits executed code that used the mshta.exe Windows binary to run an HTML application file hosted on an attacker-controlled server. Use of the binary indicated an approach known as living off the land, in which attackers use native OS functionalities and tools in an attempt to blend in with normal, non-malicious activity.

In a post published Friday, Censys researchers said that the exploitation by the TellYouThePass gang started on June 7 and mirrored past incidents that opportunistically mass scan the Internet for vulnerable systems following a high-profile vulnerability and indiscriminately targeting any accessible server. The vast majority of the infected servers have IP addresses geolocated to China, Taiwan, Hong Kong, or Japan, likely stemming from the fact that Chinese and Japanese locales are the only ones confirmed to be vulnerable, Censys researchers said in an email.

Since then, the number of infected sites—detected by observing the public-facing HTTP response serving an open directory listing showing the server’s filesystem, along with the distinctive file-naming convention of the ransom note—has fluctuated from a low of 670 on June 8 to a high of 1,800 on Monday.

Enlarge / Image tracking day-to-day compromises of PHP servers and their geolocation.

Censys

Censys researchers said in an email that they’re not entirely sure what’s causing the changing numbers.

“From our perspective, many of the compromised hosts appear to remain online, but the port running the PHP-CGI or XAMPP service stops responding—hence the drop in detected infections,” they wrote. “Another point to consider is that there are currently no observed ransom payments to the only Bitcoin address listed in the ransom notes (source). Based on these facts, our intuition is that this is likely the result of those services being decommissioned or going offline in some other manner.”

XAMPP used in production, really?

The researchers went on to say that roughly half of the compromises observed show clear signs of running XAMPP, but that estimate is likely an undercount since not all services explicitly show what software they use.

“Given that XAMPP is vulnerable by default, it’s reasonable to guess that most of the infected systems are running XAMPP,” the researchers said. This Censys query lists the infections that are explicitly affecting the platform. The researchers aren’t aware of any specific platforms other than XAMPP that have been compromised.

The discovery of compromised XAMPP servers took Will Dormann, a senior vulnerability analyst at security firm Analygence, by surprise because XAMPP maintainers explicitly say their software isn’t suitable for production systems.

“People choosing to run not-for-production software have to deal with the consequences of that decision,” he wrote in an online interview.

While XAMPP is the only platform confirmed to be vulnerable, people running PHP on any Windows system should install the update as soon as possible. The Imperva post linked above provides IP addresses, file names, and file hashes that administrators can use to determine whether they have been targeted in the attacks.

Ransomware attackers quickly weaponize PHP vulnerability with 9.8 severity rating Read More »

China state hackers infected 20,000 Fortinet VPNs, Dutch spy service says

Biz & IT, exploits, fortigate, Fortinet, Security, vpns, vulnerabilities / Blake Jones / June 12, 2024

DISCLOSURE FUBAR —

Critical code-execution flaw was under exploitation 2 months before company disclosed it.

Dan Goodin – Jun 11, 2024 10: 56 pm UTC

Hackers working for the Chinese government gained access to more than 20,000 VPN appliances sold by Fortinet using a critical vulnerability that the company failed to disclose for two weeks after fixing it, Netherlands government officials said.

The vulnerability, tracked as CVE-2022-42475, is a heap-based buffer overflow that allows hackers to remotely execute malicious code. It carries a severity rating of 9.8 out of 10. A maker of network security software, Fortinet silently fixed the vulnerability on November 28, 2022, but failed to mention the threat until December 12 of that year, when the company said it became aware of an “instance where this vulnerability was exploited in the wild.” On January 11, 2023—more than six weeks after the vulnerability was fixed—Fortinet warned a threat actor was exploiting it to infect government and government-related organizations with advanced custom-made malware.

Enter CoatHanger

The Netherlands officials first reported in February that Chinese state hackers had exploited CVE-2022-42475 to install an advanced and stealthy backdoor tracked as CoatHanger on Fortigate appliances inside the Dutch Ministry of Defense. Once installed, the never-before-seen malware, specifically designed for the underlying FortiOS operating system, was able to permanently reside on devices even when rebooted or receiving a firmware update. CoatHanger could also escape traditional detection measures, the officials warned. The damage resulting from the breach was limited, however, because infections were contained inside a segment reserved for non-classified uses.

On Monday, officials with the Military Intelligence and Security Service (MIVD) and the General Intelligence and Security Service in the Netherlands said that to date, Chinese state hackers have used the critical vulnerability to infect more than 20,000 FortiGate VPN appliances sold by Fortinet. Targets include dozens of Western government agencies, international organizations, and companies within the defense industry.

“Since then, the MIVD has conducted further investigation and has shown that the Chinese cyber espionage campaign appears to be much more extensive than previously known,” Netherlands officials with the National Cyber Security Center wrote. “The NCSC therefore calls for extra attention to this campaign and the abuse of vulnerabilities in edge devices.”

Monday’s report said that exploitation of the vulnerability started two months before Fortinet first disclosed it and that 14,000 servers were backdoored during this zero-day period. The officials warned that the Chinese threat group likely still has access to many victims because CoatHanger is so hard to detect and remove.

Netherlands government officials wrote in Monday’s report:

Since the publication in February, the MIVD has continued to investigate the broader Chinese cyber espionage campaign. This revealed that the state actor gained access to at least 20,000 FortiGate systems worldwide within a few months in both 2022 and 2023 through the vulnerability with the identifier CVE-2022-42475 . Furthermore, research shows that the state actor behind this campaign was already aware of this vulnerability in FortiGate systems at least two months before Fortinet announced the vulnerability. During this so-called ‘zero-day’ period, the actor alone infected 14,000 devices. Targets include dozens of (Western) governments, international organizations and a large number of companies within the defense industry.

The state actor installed malware at relevant targets at a later date. This gave the state actor permanent access to the systems. Even if a victim installs security updates from FortiGate, the state actor continues to have this access.

It is not known how many victims actually have malware installed. The Dutch intelligence services and the NCSC consider it likely that the state actor could potentially expand its access to hundreds of victims worldwide and carry out additional actions such as stealing data.

Even with the technical report on the COATHANGER malware, infections from the actor are difficult to identify and remove. The NCSC and the Dutch intelligence services therefore state that it is likely that the state actor still has access to systems of a significant number of victims.

Fortinet’s failure to timely disclose is particularly acute given the severity of the vulnerability. Disclosures are crucial because they help users prioritize the installation of patches. When a new version fixes minor bugs, many organizations often wait to install it. When it fixes a vulnerability with a 9.8 severity rating, they’re much more likely to expedite the update process. Given the vulnerability was being exploited even before Fortinet fixed it, the disclosure likely wouldn’t have prevented all of the infections, but it stands to reason it could have stopped some.

Fortinet officials have never explained why they didn’t disclose the critical vulnerability when it was fixed. They have also declined to disclose what the company policy is for the disclosure of security vulnerabilities. Company representatives didn’t immediately respond to an email seeking comment for this post.

China state hackers infected 20,000 Fortinet VPNs, Dutch spy service says Read More »

Maximum-severity GitLab flaw allowing account hijacking under active exploitation

Biz & IT, exploits, gitlab, Security, vulnerabilities / Blake Jones / May 3, 2024

A 10 OUT OF 10 —

The threat is potentially grave because it could be used in supply-chain attacks.

Dan Goodin – May 2, 2024 7: 02 pm UTC

A maximum severity vulnerability that allows hackers to hijack GitLab accounts with no user interaction required is now under active exploitation, federal government officials warned as data showed that thousands of users had yet to install a patch released in January.

A change GitLab implemented in May 2023 made it possible for users to initiate password changes through links sent to secondary email addresses. The move was designed to permit resets when users didn’t have access to the email address used to establish the account. In January, GitLab disclosed that the feature allowed attackers to send reset emails to accounts they controlled and from there click on the embedded link and take over the account.

While exploits require no user interaction, hijackings work only against accounts that aren’t configured to use multifactor authentication. Even with MFA, accounts remained vulnerable to password resets, but the attackers ultimately are unable to access the account, allowing the rightful owner to change the reset password. The vulnerability, tracked as CVE-2023-7028, carries a severity rating of 10 out of 10.

On Wednesday, the US Cybersecurity and Infrastructure Security Agency said it is aware of “evidence of active exploitation” and added the vulnerability to its list of known exploited vulnerabilities. CISA provided no details about the in-the-wild attacks. A GitLab representative declined to provide specifics about the active exploitation of the vulnerability.

The vulnerability, classified as an improper access control flaw, could pose a grave threat. GitLab software typically has access to multiple development environments belonging to users. With the ability to access them and surreptitiously introduce changes, attackers could sabotage projects or plant backdoors that could infect anyone using software built in the compromised environment. An example of a similar supply chain attack is the one that hit SolarWinds in 2020 and pushed malware to more than 18,000 of its customers, 100 of whom received follow-on hacks. Other recent examples of supply chain attacks are here, here, and here.

These sorts of attacks are powerful. By hacking a single, carefully selected target, attackers gain the means to infect thousands of downstream users, often without requiring them to take any action at all.

According to Internet scans performed by security organization Shadowserver, more than 2,100 IP addresses showed they were hosting one or more vulnerable GitLab instances.

The biggest concentration of IP addresses was in India, followed by the US, Indonesia, Algeria, and Thailand.

The number of IP addresses showing vulnerable instances has fallen over time. Shadowserver shows that there were more than 5,300 addresses on January 22, one week after GitLab issued the patch.

The vulnerability is classed as an improper access control flaw.

CISA has ordered all civilian federal agencies that have yet to patch the vulnerability to do so immediately. The agency made no mention of MFA, but any GitLab users who haven’t already done so should enable it, ideally with a form that complies with the FIDO industry standard.

GitLab users should also remember that patching does nothing to secure systems that have already been breached through exploits. GitLab has published incident response guidance here.

Maximum-severity GitLab flaw allowing account hijacking under active exploitation Read More »

Windows vulnerability reported by the NSA exploited to install Russian malware

Biz & IT, exploits, microsoft, Security, vulnerabilities, Windows / Mike M. / April 23, 2024

Kremlin-backed hackers have been exploiting a critical Microsoft vulnerability for four years in attacks that targeted a vast array of organizations with a previously undocumented tool, the software maker disclosed Monday.

When Microsoft patched the vulnerability in October 2022—at least two years after it came under attack by the Russian hackers—the company made no mention that it was under active exploitation. As of publication, the company’s advisory still made no mention of the in-the-wild targeting. Windows users frequently prioritize the installation of patches based on whether a vulnerability is likely to be exploited in real-world attacks.

Exploiting CVE-2022-38028, as the vulnerability is tracked, allows attackers to gain system privileges, the highest available in Windows, when combined with a separate exploit. Exploiting the flaw, which carries a 7.8 severity rating out of a possible 10, requires low existing privileges and little complexity. It resides in the Windows print spooler, a printer-management component that has harbored previous critical zero-days. Microsoft said at the time that it learned of the vulnerability from the US National Security Agency.

On Monday, Microsoft revealed that a hacking group tracked under the name Forest Blizzard has been exploiting CVE-2022-38028 since at least June 2020—and possibly as early as April 2019. The threat group—which is also tracked under names including APT28, Sednit, Sofacy, GRU Unit 26165, and Fancy Bear—has been linked by the US and the UK governments to Unit 26165 of the Main Intelligence Directorate, a Russian military intelligence arm better known as the GRU. Forest Blizzard focuses on intelligence gathering through the hacking of a wide array of organizations, mainly in the US, Europe, and the Middle East.

Since as early as April 2019, Forest Blizzard has been exploiting CVE-2022-38028 in attacks that, once system privileges are acquired, use a previously undocumented tool that Microsoft calls GooseEgg. The post-exploitation malware elevates privileges within a compromised system and goes on to provide a simple interface for installing additional pieces of malware that also run with system privileges. This additional malware, which includes credential stealers and tools for moving laterally through a compromised network, can be customized for each target.

“While a simple launcher application, GooseEgg is capable of spawning other applications specified at the command line with elevated permissions, allowing threat actors to support any follow-on objectives such as remote code execution, installing a backdoor, and moving laterally through compromised networks,” Microsoft officials wrote.

GooseEgg is typically installed using a simple batch script, which is executed following the successful exploitation of CVE-2022-38028 or another vulnerability, such as CVE-2023-23397, which Monday’s advisory said has also been exploited by Forest Blizzard. The script is responsible for installing the GooseEgg binary, often named justice.exe or DefragmentSrv.exe, then ensuring that they run each time the infected machine is rebooted.

Windows vulnerability reported by the NSA exploited to install Russian malware Read More »

“Highly capable” hackers root corporate networks by exploiting firewall 0-day

Biz & IT, exploits, Palo Alto Networks, pan-os, Security, vulnerabilities, zerodays / Ari B / April 12, 2024

The word ZERO-DAY is hidden amidst a screen filled with ones and zeroes.

Highly capable hackers are rooting multiple corporate networks by exploiting a maximum-severity zero-day vulnerability in a firewall product from Palo Alto Networks, researchers said Friday.

The vulnerability, which has been under active exploitation for at least two weeks now, allows the hackers with no authentication to execute malicious code with root privileges, the highest possible level of system access, researchers said. The extent of the compromise, along with the ease of exploitation, has earned the CVE-2024-3400 vulnerability the maximum severity rating of 10.0. The ongoing attacks are the latest in a rash of attacks aimed at firewalls, VPNs, and file-transfer appliances, which are popular targets because of their wealth of vulnerabilities and direct pipeline into the most sensitive parts of a network.

“Highly capable” UTA0218 likely to be joined by others

The zero-day is present in PAN-OS 10.2, PAN-OS 11.0, and/or PAN-OS 11.1 firewalls when they are configured to use both the GlobalProtect gateway and device telemetry. Palo Alto Networks has yet to patch the vulnerability but is urging affected customers to follow the workaround and mitigation guidance provided here. The advice includes enabling Threat ID 95187 for those with subscriptions to the company’s Threat Prevention service and ensuring vulnerability protection has been applied to their GlobalProtect interface. When that’s not possible, customers should temporarily disable telemetry until a patch is available.

Volexity, the security firm that discovered the zero-day attacks, said that it’s currently unable to tie the attackers to any previously known groups. However, based on the resources required and the organizations targeted, they are “highly capable” and likely backed by a nation-state. So far, only a single threat group—which Volexity tracks as UTA0218—is known to be leveraging the vulnerability in limited attacks. The company warned that as new groups learn of the vulnerability, CVE-2024-3400, is likely to come under mass exploitation, just as recent zero-days affecting products from the likes of Ivanti, Atlassian, Citrix, and Progress have in recent months.

“As with previous public disclosures of vulnerabilities in these kinds of devices, Volexity assesses that it is likely a spike in exploitation will be observed over the next few days by UTA0218 and potentially other threat actors who may develop exploits for this vulnerability,” company researchers wrote Friday. “This spike in activity will be driven by the urgency of this window of access closing due to mitigations and patches being deployed. It is therefore imperative that organizations act quickly to deploy recommended mitigations and perform compromise reviews of their devices to check whether further internal investigation of their networks is required.”

The earliest attacks Volexity has seen took place on March 26 in what company researchers suspect was UTA0218 testing the vulnerability by placing zero-byte files on firewall devices to validate exploitability. On April 7, the researchers observed the group trying unsuccessfully to install a backdoor on a customer’s firewall. Three days later, the group’s attacks were successfully deploying malicious payloads. Since then, the threat group has deployed custom, never-before-seen post-exploitation malware. The backdoor, which is written in the Python language, allows the attackers to use specially crafted network requests to execute additional commands on hacked devices.

“Highly capable” hackers root corporate networks by exploiting firewall 0-day Read More »

Critical takeover vulnerabilities in 92,000 D-Link devices under active exploitation

Biz & IT, D-Link, exploits, Security, vulnerabilities / Ari B / April 8, 2024

JUST ADD GET REQUEST —

D-Link won’t be patching vulnerable NAS devices because they’re no longer supported.

Dan Goodin – Apr 8, 2024 6: 56 pm UTC

Hackers are actively exploiting a pair of recently discovered vulnerabilities to remotely commandeer network-attached storage devices manufactured by D-Link, researchers said Monday.

Roughly 92,000 devices are vulnerable to the remote takeover exploits, which can be remotely transmitted by sending malicious commands through simple HTTP traffic. The vulnerability came to light two weeks ago. The researcher said they were making the threat public because D-Link said it had no plans to patch the vulnerabilities, which are present only in end-of-life devices, meaning they are no longer supported by the manufacturer.

An ideal recipe

On Monday, researchers said their sensors began detecting active attempts to exploit the vulnerabilities starting over the weekend. Greynoise, one of the organizations reporting the in-the-wild exploitation, said in an email that the activity began around 02: 17 UTC on Sunday. The attacks attempted to download and install one of several pieces of malware on vulnerable devices depending on their specific hardware profile. One such piece of malware is flagged under various names by 40 endpoint protection services.

Security organization Shadowserver has also reported seeing scanning or exploits from multiple IP addresses but didn’t provide additional details.

The vulnerability pair, found in the nas_sharing.cgi programming interface of the vulnerable devices, provide an ideal recipe for remote takeover. The first, tracked as CVE-2024-3272 and carrying a severity rating of 9.8 out of 10, is a backdoor account enabled by credentials hardcoded into the firmware. The second is a command-injection flaw tracked as CVE-2024-3273 and has a severity rating of 7.3. It can be remotely activated with a simple HTTP GET request.

Netsecfish, the researcher who disclosed the vulnerabilities, demonstrated how a hacker could remotely commandeer vulnerable devices by sending a simple set of HTTP requests to them. The code looks like this:

GET /cgi-bin/nas_sharing.cgiuser=messagebus&passwd=&cmd=15&system=

In the exploit example below, the text inside the first red rectangle contains the hardcoded credentials—username messagebus and an empty password field—while the next rectangle contains a malicious command string that has been base64 encoded.

“Successful exploitation of this vulnerability could allow an attacker to execute arbitrary commands on the system, potentially leading to unauthorized access to sensitive information, modification of system configurations, or denial of service conditions,” netsecfish wrote.

Last week, D-Link published an advisory. D-Link confirmed the list of affected devices:

Model	Region	Hardware Revision	End of Service Life	Fixed Firmware	Conclusion	Last Updated
DNS-320L	All Regions	All H/W Revisions	05/31/2020 : Link	Not Available	Retire & Replace Device	04/01/2024
DNS-325	All Regions	All H/W Revisions	09/01/2017 : Link	Not Available	Retire & Replace Device	04/01/2024
DNS-327L	All Regions	All H/W Revisions	05/31/2020 : Link	Not Available	Retire & Replace Device	04/01/2024
DNS-340L	All Regions	All H/W Revisions	07/31/2019 : Link	Not Available	Retire & Replace Device	04/01/2024

According to netsecfish, Internet scans found roughly 92,000 devices that were vulnerable.

According to the Greynoise email, exploits company researchers are seeing look like this:

GET /cgi-bin/nas_sharing.cgi?dbg=1&cmd=15&user=messagebus&passwd=&cmd=Y2QgL3RtcDsgcLnNo HTTP/1.1

Other malware invoked in the exploit attempts include:

The best defense against these attacks and others like them is to replace hardware once it reaches end of life. Barring that, users of EoL devices should at least ensure they’re running the most recent firmware. D-Link provides this dedicated support page for legacy devices for owners to locate the latest available firmware. Another effective protection is to disable UPnP and connections from remote Internet addresses unless they’re absolutely necessary and configured correctly.

Critical takeover vulnerabilities in 92,000 D-Link devices under active exploitation Read More »