CVE-2023-29409
Publication date 2 August 2023
Last updated 29 July 2025
Ubuntu priority
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| golang-1.19 | 26.04 LTS resolute | Not in release |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy | Not in release | |
| 20.04 LTS focal | Not in release | |
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release | |
| golang-1.20 | 26.04 LTS resolute | Not in release |
| 24.04 LTS noble | Not in release | |
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
|
| 18.04 LTS bionic | Not in release | |
| 16.04 LTS xenial | Not in release | |
| 14.04 LTS trusty | Not in release |
Severity score breakdown
CVSS version: CVSS v3.0
Base score
5.3 · Medium
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
References
Other references
- https://groups.google.com/g/golang-announce/c/X0b6CsSAaYI
- https://github.com/golang/go/issues/61460
- https://github.com/golang/go/commit/a51957fb0b20bb6c91d0415efca222cc9ecdb770(1.21)
- https://github.com/golang/go/commit/659f2a22076713bd2500adc82e026b6a746d8ba1(1.20)
- https://github.com/golang/go/commit/2300f7ef07718f6be4d8aa8486c7de99836e233f(1.19)
- https://www.cve.org/CVERecord?id=CVE-2023-29409