Vulnerability in Golang Go

CVE-2021-34558

The crypto/tls package of Go through 1.16.5 does not properly assert that the type of public key in an X.509 certificate matches the expected type when doing a RSA based key exchange, allowing a malicious TLS server to cause a TLS client to panic.

Vulnerability class: Improper Certificate Validation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.070 (93.9th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 93.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-34558: held from 0.070 to 0.070.

EPSS over last 30 days · oldest: 0.070 · newest: 0.070 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-34558?
CVE-2021-34558 is a medium-severity vulnerability in Golang Go, classified under Improper Certificate Validation. CVSS score: 6.5/10. Published 2021-07-15.
How severe is CVE-2021-34558?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2021-34558 known to be exploited?
17 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.