CVE-2025-69420
📋 TL;DR
A type confusion vulnerability in OpenSSL's TimeStamp Response verification allows attackers to cause denial of service by providing malformed timestamp responses. Applications that verify timestamp responses using TS_RESP_verify_response() are affected. The vulnerability exists in multiple OpenSSL versions but has low severity due to limited usage of the TimeStamp protocol.
💻 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 →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
Application crash leading to denial of service for services that verify timestamp responses
Likely Case
Limited denial of service affecting specific timestamp verification functionality
If Mitigated
No impact if timestamp response verification is disabled or not used
🎯 Exploit Status
Exploitation requires providing malformed TimeStamp Response to applications that verify them. No authentication required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patched in commits referenced in CVE details
Vendor Advisory: https://github.com/openssl/openssl/commit/27c7012c91cc986a598d7540f3079dfde2416eb9
Restart Required: Yes
Instructions:
1. Update OpenSSL to patched version 2. Recompile applications linked against OpenSSL 3. Restart affected services
🔧 Temporary Workarounds
Disable TimeStamp Response verification
allDisable or remove timestamp response verification functionality if not required
Configure applications to not use TS_RESP_verify_response()
🧯 If You Can't Patch
- Implement network filtering to block malformed timestamp responses
- Monitor for application crashes related to timestamp verification
🔍 How to Verify
Check if Vulnerable:
Check OpenSSL version with 'openssl version' commandCheck Version:
openssl versionVerify Fix Applied:
Verify OpenSSL version is updated and applications are recompiled📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing timestamp responses
- Segmentation faults in OpenSSL timestamp functions
Network Indicators:
- Malformed timestamp response traffic to applications
SIEM Query:
Process crashes with OpenSSL timestamp functions in stack trace🔗 References
- https://github.com/openssl/openssl/commit/27c7012c91cc986a598d7540f3079dfde2416eb9
- https://github.com/openssl/openssl/commit/4e254b48ad93cc092be3dd62d97015f33f73133a
- https://github.com/openssl/openssl/commit/564fd9c73787f25693bf9e75faf7bf6bb1305d4e
- https://github.com/openssl/openssl/commit/5eb0770ffcf11b785cf374ff3c19196245e54f1b
- https://github.com/openssl/openssl/commit/a99349ebfc519999edc50620abe24d599b9eb085
- https://openssl-library.org/news/secadv/20260127.txt
