CVE-2023-29409

Description

Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.

CVSS Metrics

• v3.1•MEDIUM•Score: 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Trends

Current EPSS score: 0.12%• Percentile: 31%

Techniques & Countermeasures

• CWE-400•Uncontrolled Resource Consumption

  The product does not properly control the allocation and maintenance of a limited resource.

Affected Systems

• go standard library•crypto/tls

  < 1.19.12 | ≥ 1.20.0-0, < 1.20.7 | ≥ 1.21.0-0, < 1.21.0-rc.4

• golang•go

  < 1.19.12 | ≥ 1.20.0, < 1.20.7 | 1.21.0:rc1 | 1.21.0:rc2 | 1.21.0:rc3

• Go•stdlib

  ≥ 1.21.0-0, < 1.21.0-rc.4

References (6)

• https://go.dev/issue/61460
• https://go.dev/cl/515257
• https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI/m/Efv5DbZ9AwAJ
• https://pkg.go.dev/vuln/GO-2023-1987
• https://security.netapp.com/advisory/ntap-20230831-0010/
• https://security.gentoo.org/glsa/202311-09