Bug 2002830 (CVE-2021-40530)

Summary: CVE-2021-40530 cryptopp: ElGamal implementation allows plaintext recovery
Product: [Other] Security Response Reporter: Guilherme de Almeida Suckevicz <gsuckevi>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED UPSTREAM QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: alekcejk, aurelien, kwizart, vascom2
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Last Closed: 2021-09-10 00:21:17 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2002831, 2002832    
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Description Guilherme de Almeida Suckevicz 2021-09-09 19:28:56 UTC 
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.

References:
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
https://eprint.iacr.org/2021/923
Comment 1 Guilherme de Almeida Suckevicz 2021-09-09 19:29:14 UTC 
Created cryptopp tracking bugs for this issue:

Affects: epel-all [bug 2002832]
Affects: fedora-all [bug 2002831]
Comment 2 Product Security DevOps Team 2021-09-10 00:21:17 UTC 
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.