Bug 811915 (CVE-2021-40530)

Summary:	<dev-libs/crypto++-8.6.0: ElGamal plaintext recovery (CVE-2021-40530)
Product:	Gentoo Security	Reporter:	John Helmert III <ajak>
Component:	Vulnerabilities	Assignee:	Gentoo Security <security>
Status:	IN_PROGRESS ---
Severity:	minor	CC:	sam
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	https://github.com/weidai11/cryptopp/issues/1059
Whiteboard:	B4 [glsa? cleanup]
Package list:		Runtime testing required:	---
Bug Depends on:	817932
Bug Blocks:

Description John Helmert III archtester

2021-09-07 01:44:37 UTC

CVE-2021-40530 (https://ibm.github.io/system-security-research-updates/2021/07/20/insecurity-elgamal-pt1, https://ibm.github.io/system-security-research-updates/2021/09/06/insecurity-elgamal-pt2):

The ElGamal implementation in Crypto++ through 8.5 allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP.


No references to upstream in CVE references so not sure what needs to be done.

Comment 1 John Helmert III archtester

2021-09-25 18:36:23 UTC

8.6.0 claims to finally fix this.