Bug 2254426 (CVE-2023-50781)

Summary:	CVE-2023-50781 m2crypto: Bleichenbacher timing attacks in the RSA decryption API - incomplete fix for CVE-2020-25657
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	CC:	gtanzill, hkario, michal.skrivanek, mminar, mperina, rbiba, sbonazzo, sskracic
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A flaw was found in m2crypto. This issue may allow a remote attacker to decrypt captured messages in TLS servers that use RSA key exchanges, which may lead to exposure of confidential or sensitive data.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2254436, 2254437, 2254734, 2254735
Bug Blocks:	2254421

Description Robb Gatica 2023-12-13 21:20:33 UTC

Description:
The fix for CVE-2020-25657 is not addressing the leakage in the RSA decryption. Because of the API design, the fix is generally not believed to be possible to be fully addressed. The issue can be mitigated by using a cryptographic backend that implements implicit rejection (Marvin workaround). Only applications that use RSA decryption with PKCS#1 v1.5 padding are affected.

References:
https://gitlab.com/m2crypto/m2crypto/-/issues/342
https://people.redhat.com/~hkario/marvin/
https://github.com/openssl/openssl/pull/13817

Comment 2 Robb Gatica 2023-12-13 22:15:27 UTC

Created m2crypto tracking bugs for this issue:

Affects: fedora-all [bug 2254436]

Comment 6 Robb Gatica 2023-12-15 16:16:25 UTC

Created pywbem tracking bugs for this issue:

Affects: fedora-all [bug 2254734]


Created virt-who tracking bugs for this issue:

Affects: fedora-all [bug 2254735]