CVE-2012-5573: Medium severity tor project tor vulnerability
It was reported [1],[2] that Tor suffered from a denial of service vulnerability due to an error when handling SENDME cells. This could be exploited to cause excessive consumption of memory resources within an entry node.
This is fixed in upstream version 0.2.3.25 (git [3]).
[1] https://secunia.com/advisories/51329/ [2] https://trac.torproject.org/projects/tor/ticket/6252 [3] https://gitweb.torproject.org/arma/tor.git/commitdiff/b9b54568c0bb64c32bd0b362954bdbc8c1234b16
Other sources
The connectionedgeprocessrelaycell function in or/relay.c in Tor before 0.2.3.25 maintains circuits even if an unexpected SENDME cell arrives, which might allow remote attackers to cause a denial of service (memory consumption or excessive cell reception rate) or bypass intended flow-control restrictions via a RELAYCOMMANDSENDME command.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2012-5573?
CVE-2012-5573 has been classified as a denial of service vulnerability due to excessive memory consumption.
How do I fix CVE-2012-5573?
To mitigate CVE-2012-5573, upgrade to upstream version 0.2.3.25 or later of Tor.
What versions are affected by CVE-2012-5573?
CVE-2012-5573 affects various versions of Tor prior to 0.2.3.25, including several release candidates and earlier versions.
What type of attack can exploit CVE-2012-5573?
CVE-2012-5573 can be exploited by sending specially crafted SENDME cells to overwhelm an entry node's memory.
Is there a patch available for CVE-2012-5573?
Yes, a patch is included in the Tor release version 0.2.3.25 and later to address CVE-2012-5573.