Bug 2255127 (CVE-2023-50979)

Summary:	CVE-2023-50979 cryptopp: side-channel leakage during decryption with PKCS#1v1.5 padding (Marvin)
Product:	[Other] Security Response	Reporter:	Robb Gatica <rgatica>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A security flaw was discovered in Crypto++ (cryptopp). This issue may allow a remote attacker to decrypt captured messages in TLS servers, which may lead to exposure of confidential or sensitive data.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2255128, 2255129
Bug Blocks:	2255124

Description Robb Gatica 2023-12-18 19:27:28 UTC

Reference: https://github.com/weidai11/cryptopp/issues/1247

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Crypto++ Issue Report

I've verified that the Crypto++ is vulnerable to the Marvin Attack—a timing variant of the well-known Bleichenbacher attack.

I've executed the test on ArchLinux, using crypto++ 8.9.0 from the Arch repository.
The reproducer is available in the marvin-toolkit repository. It was compiled with a simple g++ -o time_decrypt -lcryptopp time_decrypt.cpp.

When executed on AMD Ryzen 5 5600X, I'm able to detect a side-channel signal when performing decryption with PKCS#1 v1.5 padding. The results are statistically significant with just few hundred measurement pairs, but below I'm showing results of a run with 100k repeats to show the size of the side-channel more clearly.

Comment 1 Robb Gatica 2023-12-18 19:36:39 UTC

Created cryptopp tracking bugs for this issue:

Affects: epel-all [bug 2255128]
Affects: fedora-all [bug 2255129]