CVE-2020-26939

NameCVE-2020-26939
DescriptionIn Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-2433-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
bouncycastle (PTS)buster1.60-1vulnerable
buster (security)1.60-1+deb10u1vulnerable
bullseye1.68-2fixed
bookworm1.72-2fixed
sid, trixie1.77-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
bouncycastlesourcestretch1.56-1+deb9u3DLA-2433-1
bouncycastlesource(unstable)1.61-1

Notes

[buster] - bouncycastle <no-dsa> (Minor issue)
https://github.com/bcgit/bc-java/wiki/CVE-2020-26939
https://github.com/bcgit/bc-java/commit/930f8b274c4f1f3a46e68b5441f1e7fadb57e8c1 (r1rv61)

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