CVE-2012-3517: Double Free
A read from already freed memory and double free flaws were found in the way Tor, a connection-based low-latency anonymous communication system, performed processing of certain failing DNS requests. A remote attacker could issue a specially-crafted DNS request that, when processed would lead to tor executable crash.
Upstream ticket: [1] https://trac.torproject.org/projects/tor/ticket/6480
Relevant patch: [2] https://gitweb.torproject.org/tor.git/commitdiff/62637fa22405278758febb1743da9af562524d4c
References: [3] https://lists.torproject.org/pipermail/tor-announce/2012-August/000086.html [4] https://bugzilla.novell.com/showbug.cgi?id=776642
Other sources
Use-after-free vulnerability in dns.c in Tor before 0.2.2.38 might allow remote attackers to cause a denial of service (daemon crash) via vectors related to failed DNS requests.
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2012-3517?
CVE-2012-3517 is rated as high severity due to its potential to allow remote code execution and denial of service attacks.
How do I fix CVE-2012-3517?
To fix CVE-2012-3517, upgrade Tor to version 0.2.2.39 or later.
Who is affected by CVE-2012-3517?
CVE-2012-3517 affects all versions of Tor up to and including 0.2.2.38.
What type of vulnerability is CVE-2012-3517?
CVE-2012-3517 is a vulnerability that involves a read from already freed memory and double free issues in Tor.
Can CVE-2012-3517 be exploited remotely?
Yes, CVE-2012-3517 can be exploited remotely through specially crafted DNS requests.