CVE-2020-12402

medium
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
5.5

Description

During RSA key generation, bignum implementations used a variation of the Binary Extended Euclidean Algorithm which entailed significantly input-dependent flow. This allowed an attacker able to perform electromagnetic-based side channel attacks to record traces leading to the recovery of the secret primes. *Note:* An unmodified Firefox browser does not generate RSA keys in normal operation and is not affected, but products built on top of it might. This vulnerability affects Firefox < 78.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2020-12402

vendor Authored 2026-05-27

Vendor advisory: rocky — https://errata.rockylinux.org/RLSA-2020:3280

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2020-12402.html

OS impact

OSVersionStatusFixed in
suse slesaffected
rockylinux rocky8fixed
debian debianbookwormfixed2:3.53.1-1
debian debianbullseyefixed2:3.53.1-1
debian debianforkyfixed2:3.53.1-1
debian debiansidfixed2:3.53.1-1
debian debiantrixiefixed2:3.53.1-1

References

Verify integrity in audit chain (admin only). AS-IS.