GHSA-52xf-5p2m-9wrv – s2n-tls

Package

Manager: cargo
Name: s2n-tls
Vulnerable Version: >=0 <0.2.7

Severity

Level: Low

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:U/RC:C

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS: N/A pctlN/A

Details

s2n-tls has a potentially observable differences in RSA premaster secret handling When receiving a message from a client that sent an invalid RSA premaster secret, an issue in s2n-tls results in the server performing additional processing when the premaster secret contains an incorrect client hello version. While no practical attack on s2n-tls has been demonstrated, this causes a small timing difference which could theoretically be used as described in the Marvin Attack [1]. We would like to thank Hubert Kario [2] for reporting this issue. ### Impact The extent of this issue is a timing difference. No practical attack on s2n-tls has been demonstrated. This issue affects server applications that permit RSA key exchange. Applications that use the default, built-in blinding feature or properly implement self-service blinding are not affected. Impacted versions: <= v1.4.15. ### Patches The patch is included in v1.4.16 [3]. ### Workarounds Applications can work around this issue by using an s2n-tls security policy that disallows RSA key exchange. If you have any questions or comments about this advisory we ask that you contact AWS/Amazon Security via our vulnerability reporting page [4] or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue. [1] https://people.redhat.com/~hkario/marvin/ [2] https://github.com/tomato42 [3] https://github.com/aws/s2n-tls/releases/tag/v1.4.16 [4] https://aws.amazon.com/security/vulnerability-reporting

Metadata

Created: 2024-06-06T14:26:18Z
Modified: 2024-06-06T14:26:18Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/06/GHSA-52xf-5p2m-9wrv/GHSA-52xf-5p2m-9wrv.json
CWE IDs: ["CWE-203"]
Alternative ID: N/A
Finding: F026
Auto approve: 1