CVE-2024-13176: openssl Covert Timing Channel

Vulnerability summary

CVE-2024-13176 is a medium (CVSS 4.1) Covert Timing Channel vulnerability in openssl. EPSS estimates a 0.61% chance of exploitation in the next 30 days, higher than 48.3% of scored vulnerabilities.

Timeline

1. 20-01-2025
   PublishedVulnerability first disclosed.
2. 18-03-2026
   Last modifiedVulnerability information updated.

Description

Issue summary: A timing side-channel which could potentially allow recovering the private key exists in the ECDSA signature computation. Impact summary: A timing side-channel in ECDSA signature computations could allow recovering the private key by an attacker. However, measuring the timing would require either local access to the signing application or a very fast network connection with low latency. There is a timing signal of around 300 nanoseconds when the top word of the inverted ECDSA nonce value is zero. This can happen with significant probability only for some of the supported elliptic curves. In particular the NIST P-521 curve is affected. To be able to measure this leak, the attacker process must either be located in the same physical computer or must have a very fast network connection with low latency. For that reason the severity of this vulnerability is Low. The FIPS modules in 3.4, 3.3, 3.2, 3.1 and 3.0 are affected by this issue.

• CWE-385Covert Timing ChannelCovert timing channels convey information by modulating some aspect of system behavior over time, so that the program receiving the information can observe system behavior and infer protected information.