CVE-2023-29409

Large RSA keys can cause high CPU usage in crypto/tls

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.

Category

5.3
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.08%
Vendor Advisory go.dev Vendor Advisory google.com Vendor Advisory go.dev
Affected: Go standard library crypto/tls
Published at:
Updated at:

References

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

Frequently Asked Questions

What is the severity of CVE-2023-29409?
CVE-2023-29409 has been scored as a medium severity vulnerability.
How to fix CVE-2023-29409?
To fix CVE-2023-29409, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-29409 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-29409 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-29409?
CVE-2023-29409 affects Go standard library crypto/tls.
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