Bug 1981510

Summary:	mbedtls: Local side channel attack on RSA
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	ms, redhat-bugzilla
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
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Clone Of:		Environment:
Last Closed:	2021-07-12 22:40:26 UTC	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:	1981511, 1981512
Bug Blocks:

Description Pedro Sampaio 2021-07-12 17:44:49 UTC

The modular exponentiation operation in RSA uses a sliding window algorithm, with a memory access pattern that depends on the bits of the secret key.
Exponent blinding is used as a counter-measure: it prevents an attacker from correlating informations gathered on successive operation, but researchers found a way to recover enough information by observing a single operation, therefore by-passing this counter-measure.

References:

https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2021-07-1

Comment 1 Pedro Sampaio 2021-07-12 17:46:16 UTC

Created mbedtls tracking bugs for this issue:

Affects: epel-all [bug 1981512]
Affects: fedora-all [bug 1981511]

Comment 2 Product Security DevOps Team 2021-07-12 22:40:26 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.