CVE-2023-29409
Large RSA keys can cause high CPU usage in crypto/tls
- Published
- Updated
- Reserved
- Assigned by
- Go
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
- EPSS (exploitation in 30 days)
- 1.6% · top 24% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Weakness
- CWE-400: Uncontrolled Resource Consumption
- CWE-400 (opens in a new tab)All about CWE-400 and its CVEs
Affected products
Go standard library · crypto/tls
- affected < 1.19.12
- affected 1.20.0-0 – < 1.20.7
- affected 1.21.0-0 – < 1.21.0-rc.4
References (6)
- https://go.dev/issue/61460 (opens in a new tab)x_transferred
- https://go.dev/cl/515257 (opens in a new tab)x_transferred
- https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI/m/Efv5DbZ9AwAJ (opens in a new tab)x_transferred
- https://pkg.go.dev/vuln/GO-2023-1987 (opens in a new tab)x_transferred
- https://security.netapp.com/advisory/ntap-20230831-0010/ (opens in a new tab)x_transferred
- https://security.gentoo.org/glsa/202311-09 (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2023-29409)Record last updated .