CVE-2016-2178: Medium severity OpenSSL OpenSSL vulnerability
It was discovered that OpenSSL did not always use constant time operations when computing Digital Signature Algorithm (DSA) signatures. A local attacker could possibly use this flaw to obtain a private DSA key belonging to another user or service running on the same system.
Other sources
Operations in the DSA signing algorithm should run in constant time in order to avoid side channel attacks. A flaw in the OpenSSL DSA implementation means that a non-constant time codepath is followed for certain operations. This has been demonstrated through a cache-timing attack to be sufficient for an attacker to recover the private DSA key.
Upstream fix:
https://git.openssl.org/?p=openssl.git;a=commitdiff;h=d168705e11526a4b487640c7cac5b53ee3646cbc https://git.openssl.org/?p=openssl.git;a=commitdiff;h=3681a4558c13198944e6f7f149c4be188e076e14
— Red Hat
The dsasignsetup function in crypto/dsa/dsaossl.c in OpenSSL through 1.0.2h does not properly ensure the use of constant-time operations, which makes it easier for local users to discover a DSA private key via a timing side-channel attack.
Affected Software
Remediation
Patch Available
Patch Available
Event History
Parent advisories
This vulnerability appears in the following advisories.
Frequently Asked Questions
What is the severity of CVE-2016-2178?
CVE-2016-2178 is rated as a high severity vulnerability due to its potential to allow attackers to obtain a private DSA key.
How do I fix CVE-2016-2178?
To fix CVE-2016-2178, you should upgrade to the patched versions of OpenSSL and related packages as specified in the security advisories.
Who is affected by CVE-2016-2178?
CVE-2016-2178 affects systems using certain versions of OpenSSL that do not implement constant time operations for DSA signatures.
What types of attacks can be performed using CVE-2016-2178?
A local attacker can exploit CVE-2016-2178 to potentially gain access to private DSA keys belonging to other users or services on the same system.
Are there any known exploits for CVE-2016-2178?
While there are no specific public exploits reported for CVE-2016-2178, the nature of the vulnerability suggests it could be leveraged in targeted attacks.