CVE-2025-11187
📋 TL;DR
This vulnerability in OpenSSL allows attackers to cause denial of service or potentially execute arbitrary code by crafting malicious PKCS#12 files that trigger buffer overflows or NULL pointer dereferences during MAC verification. It affects OpenSSL 3.4, 3.5, and 3.6 when processing untrusted PKCS#12 files using PBMAC1. Applications that parse PKCS#12 files from untrusted sources are at risk.
💻 Affected Systems
- OpenSSL
📦 What is this software?
Openssl by Openssl
OpenSSL is a robust, commercial-grade toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. It provides cryptographic functions and is one of the most widely used libraries for implementing secure communications in applications worldwide.
Learn more about Openssl →Openssl by Openssl
OpenSSL is a robust, commercial-grade toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. It provides cryptographic functions and is one of the most widely used libraries for implementing secure communications in applications worldwide.
Learn more about Openssl →Openssl by Openssl
OpenSSL is a robust, commercial-grade toolkit for the Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols. It provides cryptographic functions and is one of the most widely used libraries for implementing secure communications in applications worldwide.
Learn more about Openssl →⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if platform mitigations are bypassed.
Likely Case
Application crash causing denial of service when processing malicious PKCS#12 files.
If Mitigated
No impact if applications don't process untrusted PKCS#12 files or use unaffected versions.
🎯 Exploit Status
Exploitation requires crafting malicious PKCS#12 files and convincing users/applications to process them. Code execution depends on platform mitigations.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply latest security updates for OpenSSL 3.4, 3.5, and 3.6
Vendor Advisory: https://openssl-library.org/news/secadv/20260127.txt
Restart Required: Yes
Instructions:
1. Check current OpenSSL version with 'openssl version'
2. Update OpenSSL using your package manager (apt-get update && apt-get upgrade openssl on Debian/Ubuntu, yum update openssl on RHEL/CentOS)
3. Restart all services using OpenSSL
4. Verify update with 'openssl version'
🔧 Temporary Workarounds
Disable PKCS#12 processing
allConfigure applications to reject PKCS#12 files or disable PKCS#12 support
Application-specific configuration required
Input validation
allImplement strict validation of PKCS#12 files before processing
Implement file validation in application code
🧯 If You Can't Patch
- Restrict PKCS#12 file processing to trusted sources only
- Implement network segmentation to isolate systems processing PKCS#12 files
🔍 How to Verify
Check if Vulnerable:
Run 'openssl version' and check if version is 3.4.x, 3.5.x, or 3.6.xCheck Version:
openssl versionVerify Fix Applied:
Check OpenSSL version is updated to a patched release and test PKCS#12 file processing📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing PKCS#12 files
- Segmentation faults in OpenSSL-related processes
Network Indicators:
- Unusual PKCS#12 file transfers to applications
SIEM Query:
Process crashes with OpenSSL library in stack trace AND file extension .p12 or .pfx in recent file operations🔗 References
- https://github.com/openssl/openssl/commit/205e3a55e16e4bd08c12fdbd3416ab829c0f6206
- https://github.com/openssl/openssl/commit/8caf359d6e46fb413e8f5f0df765d2e8a51df4e8
- https://github.com/openssl/openssl/commit/e1079bc17ed93ff16f6b86f33a2fe3336e78817e
- https://openssl-library.org/news/secadv/20260127.txt
