A vulnerability in Tor was reported  that could allow a malicious remote attacker to cause a denial of service. This vulnerability is due to a boundary error within the policy_summarize() function in src/or/policies.c which can be exploited to crash a Tor directory authority.
Upstream announced the release of 0.2.1.30  that is noted to correct this flaw.
Created tor tracking bugs for this issue
Affects: fedora-13 [bug 705193]
Affects: fedora-14 [bug 705194]
Affects: epel-5 [bug 671263]
The upstream fix is here:
This was assigned CVE-2011-1924.
fixed long time ago