CVE-2025-4802

What it actually does

Allows attacker-controlled loading of shared libraries via an untrusted LD_LIBRARY_PATH in statically compiled setuid binaries that invoke dlopen (including via setlocale or NSS functions like getaddrinfo) in glibc 2.27-2.38.

Why it matters to the business

Attackers can obtain elevated privileges on affected Ubuntu Linux systems, enabling unauthorized access, data theft, or persistence that disrupts operations and increases breach costs.

How an attack unfolds

An attacker sets a malicious LD_LIBRARY_PATH pointing to a crafted library, then invokes a vulnerable setuid binary that performs dlopen after setlocale or NSS calls, causing the library to load with elevated privileges and execute attacker code.

How to fix it

Upgrade affected packages to the listed fixed versions: linux (Ubuntu 24.04 LTS) to 6.8.0-50.51, linux-aws (Ubuntu 24.04 LTS) to 6.8.0-1020.22, linux-azure (Ubuntu 24.04 LTS) to 6.8.0-1020.23. Apply updates immediately across all instances and verify glibc is no longer in the vulnerable range.

How to confirm the fix worked

Confirm package versions match or exceed the fixed releases using apt or dpkg, test that LD_LIBRARY_PATH is ignored or sanitized in setuid binaries, and scan for any remaining glibc 2.27-2.38 installations.

Typical attack path

1. Identify a statically compiled setuid binary that calls dlopen or NSS functions
2. Craft a malicious shared library and place it in a writable directory
3. Export LD_LIBRARY_PATH to reference the malicious library location
4. Execute the target binary to trigger library loading under setuid context
5. Execute arbitrary code with elevated privileges

How to detect it

Review process execution logs and environment variable captures for unexpected LD_LIBRARY_PATH values preceding setuid binary launches; inspect auditd or syslog entries around NSS or setlocale calls in privileged processes for anomalous library loads.

• LD_LIBRARY_PATH=.*\.so
• setuid.*dlopen
• getaddrinfo.*library load

What your security team should do

• Prioritize patching all Ubuntu 24.04 LTS systems within the next 7 days due to privilege escalation risk
• Restrict use of LD_LIBRARY_PATH in privileged contexts via system policies
• Audit setuid binaries for dlopen usage and rebuild as needed
• Monitor for new exploit code given the public description