Researchers released exploit code for actively exploited Palo Alto PAN-OS bug

Researchers released an exploit code for the actively exploited vulnerability CVE-2024-3400 in Palo Alto Networks’ PAN-OS.

Researchers at watchTowr Labs have released a technical analysis of the vulnerability CVE-2024-3400 in Palo Alto Networks’ PAN-OS and a proof-of-concept exploit that can be used to execute shell commands on vulnerable firewalls.

CVE-2024-3400 (CVSS score of 10.0) is a critical command injection vulnerability in Palo Alto Networks PAN-OS software. An unauthenticated attacker can exploit the flaw to execute arbitrary code with root privileges on affected firewalls. This flaw impacts PAN-OS 10.2, PAN-OS 11.0, and PAN-OS 11.1 firewalls configured with GlobalProtect gateway or GlobalProtect portal (or both) and device telemetry enabled.

Palo Alto Networks and Unit 42 are investigating the activity related to CVE-2024-3400 PAN-OS flaw and discovered that threat actors have been exploiting it since March 26, 2024.

The researchers are tracking this cluster of activity, conducted by an unknown threat actor, under the name Operation MidnightEclipse.

“Palo Alto Networks is aware of malicious exploitation of this issue. We are tracking the initial exploitation of this vulnerability under the name Operation MidnightEclipse, as we assess with high confidence that known exploitation we’ve analyzed thus far is limited to a single threat actor.” reads the report. “We also assess that additional threat actors may attempt exploitation in the future.”

Upon exploiting the flaw, the threat actor was observed creating a cronjob that would run every minute to access commands hosted on an external server that would execute via bash.

The researchers were unable to access the commands executed by the attackers, however, they believe threat actors attempted to deploy a second Python-based backdoor on the vulnerable devices.

Researchers at cybersecurity firm Volexity referred this second Python backdor as UPSTYLE.

The threat actor, tracked by Volexity as UTA0218, remotely exploited the firewall device to establish a reverse shell and install additional tools. Their primary objective was to extract configuration data from the devices and then use it as a foothold to expand laterally within the targeted organizations.

Now watchTowr Labs released another detection artifact generator tool in the form of an HTTP request

“As we can see, we inject our command injection payload into the SESSID cookie value – which, when a Palo Alto GlobalProtect appliance has telemetry enabled – is then concatenated into a string and ultimately executed as a shell command.” reads the analysis published by watchTowr Labs.

“Something-something-sophistication-levels-only-achievable-by-a-nation-state-something-something.”

Justin Elze, CTO at TrustedSec, also published the exploit used in attacks in the wild.

This week, US CISA added the vulnerability CVE-2024-3400 to its Known Exploited Vulnerabilities (KEV) catalog, ordering U.S. federal agencies to address it by April 19th.

Pierluigi Paganini

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(SecurityAffairs – hacking, PAN-OS)