PT-2020-16560 · Legion Of The Bouncy Castle · Legion Of The Bouncy Castle Bc

Published 2020-11-02 · Updated 2025-07-17 · CVE-2020-26939

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Name of the Vulnerable Software and Affected Versions Legion of the Bouncy Castle BC versions 1.61 and earlier Legion of the Bouncy Castle BC-FJA versions 1.0.1.2 and earlier

Description The issue allows attackers to obtain sensitive information about a private exponent due to observable differences in behavior to error inputs. This occurs in the org.bouncycastle.crypto.encodings.OAEPEncoding class. 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.

Recommendations For Legion of the Bouncy Castle BC versions 1.61 and earlier, update to version 1.61 or later. For Legion of the Bouncy Castle BC-FJA versions 1.0.1.2 and earlier, update to version 1.0.1.2 or later. As a temporary workaround, consider restricting access to the org.bouncycastle.crypto.encodings.OAEPEncoding class until a patch is available.

Exploit

Fix

Side Channel Attack

Weakness Enumeration

CWE-203

Related Identifiers

CVE-2020-26939

DLA-2433-1

GHSA-72M5-FVVV-55M6

Affected Products

Legion Of The Bouncy Castle Bc

References · 24

• 🔥 https://github.com/bcgit/bc-java/wiki/CVE-2020-26939 · Exploit
• https://osv.dev/vulnerability/DEBIAN-CVE-2020-26939 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2020-26939 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2020-26939 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2020-26939 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-26939 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2020-26939 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-72m5-fvvv-55m6 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2020-26939 · Vendor Advisory
• https://osv.dev/vulnerability/DLA-2433-1 · Vendor Advisory
• https://github.com/bcgit/bc-java/commit/930f8b274c4f1f3a46e68b5441f1e7fadb57e8c1 · Note
• https://t.me/cvenotify/14986 · Telegram Post
• https://t.me/cvenotify/5727 · Telegram Post
• https://lists.apache.org/thread.html/r8c36ba34e80e05eecb1f80071cc834d705616f315b634ec0c7d8f42e@%3Cissues.solr.apache.org%3E · Note
• https://t.me/cvenotify/5164 · Telegram Post