buf_pullup in Tor before 0.2.4.26 and 0.2.5.x before 0.2.5.11 does not properly handle unexpected arrival times of buffers with invalid layouts, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via crafted packets.

Update to upstream release 0.2.5.12. Update to upstream release 0.2.5.11.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Update to upstream release 0.2.5.11.

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Tor was updated to 0.2.4.26 to fix several security issues :

The release: Contains several medium-level security fixes for relays and exit nodes and also updates the list of directory authorities.

  - Directory authority updates

  - relay crashes trough assertion (CVE-2015-2688)

  - exit node crash through assertion under high DNS load     (CVE-2015-2689)

  - update geoip/geoip6 to the March 3 2015

Several denial-of-service issues have been discovered in Tor, a connection-based low-latency anonymous communication system.

  - Jowr discovered that very high DNS query load on a relay     could trigger an assertion error.
  - A relay could crash with an assertion error if a buffer     of exactly the wrong layout was passed to buf_pullup()     at exactly the wrong time.

ID	Name	Product	Family	Severity
82969	Fedora 22 : tor-0.2.5.12-1.fc22 (2015-5890)	Nessus	Fedora Local Security Checks	medium
82611	Fedora 21 : tor-0.2.5.11-1.fc21 (2015-4725)	Nessus	Fedora Local Security Checks	medium
82598	Fedora 20 : tor-0.2.5.11-1.fc20 (2015-4478)	Nessus	Fedora Local Security Checks	medium
82246	openSUSE Security Update : tor (openSUSE-2015-261)	Nessus	SuSE Local Security Checks	high
82001	Debian DSA-3203-1 : tor - security update	Nessus	Debian Local Security Checks	high

Detections

Analytics

CVE-2015-2688

high

Tenable Plugins

medium

medium

medium

high

high