SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2023-29409

Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures.

MEDIUM 5.3EPSS 1.59%

Does this matter?

Lower severity and a low EPSS score (1.59%). Track it; it rarely justifies an emergency change on its own.

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 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS
1.59% probability · 74th percentile
CISA KEV
Not listed
Weakness
CWE-400
Affected
golang/go
Source
security@golang.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.