Tor before 0.2.2.34, when configured as a bridge, accepts the CREATE and CREATE_FAST values in the Command field of a cell within an OR connection that it initiated, which allows remote relays to enumerate bridges by using these values.

Updated tor package fixes security vulnerabilities :

Tor before 0.2.2.34, when configured as a client or bridge, sends a TLS certificate chain as part of an outgoing OR connection, which allows remote relays to bypass intended anonymity properties by reading this chain and then determining the set of entry guards that the client or bridge had selected (CVE-2011-2768).

Tor before 0.2.2.34, when configured as a bridge, accepts the CREATE and CREATE_FAST values in the Command field of a cell within an OR connection that it initiated, which allows remote relays to enumerate bridges by using these values (CVE-2011-2769).

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 (CVE-2012-3517).

The networkstatus_parse_vote_from_string function in routerparse.c in Tor before 0.2.2.38 does not properly handle an invalid flavor name, which allows remote attackers to cause a denial of service (out-of-bounds read and daemon crash) via a crafted (1) vote document or (2) consensus document (CVE-2012-3518).

routerlist.c in Tor before 0.2.2.38 uses a different amount of time for relay-list iteration depending on which relay is chosen, which might allow remote attackers to obtain sensitive information about relay selection via a timing side-channel attack (CVE-2012-3519).

The compare_tor_addr_to_addr_policy function in or/policies.c in Tor before 0.2.2.39, and 0.2.3.x before 0.2.3.21-rc, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a zero-valued port field that is not properly handled during policy comparison (CVE-2012-4419).

Tor before 0.2.2.39, when waiting for a client to renegotiate, allowed it to add bytes to the input buffer, allowing a crash to be caused remotely (tor-5934, tor-6007).

Denial of Service vulnerability in Tor before 0.2.3.25, due to an error when handling SENDME cells and can be exploited to cause excessive consumption of memory resources within an entry node (SA51329, CVE-2012-5573).

The version of Tor shipped in MBS1 did not have correctly formed systemd unit and thus failed to start.

This updated version corrects this problem and restores working behaviour.

The remote host is affected by the vulnerability described in GLSA-201201-12 (Tor: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in Tor:
      When configured as client or bridge, Tor uses the same TLS         certificate chain for all outgoing connections (CVE-2011-2768).
      When configured as a bridge, Tor relays can distinguish incoming         bridge connections from client connections (CVE-2011-2769).
      An error in or/buffers.c could result in a heap-based buffer overflow         (CVE-2011-2778).
  Impact :

    A remote attacker could possibly execute arbitrary code or cause a       Denial of Service. Furthermore, a remote relay the user is directly       connected to may be able to disclose anonymous information about that       user or enumerate bridges in the user's connection.
  Workaround :

    There is no known workaround at this time.

.
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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.

It has been discovered by 'frosty_un' that a design flaw in Tor, an online privacy tool, allows malicious relay servers to learn certain information that they should not be able to learn. Specifically, a relay that a user connects to directly could learn which other relays that user is connected to directly. In combination with other attacks, this issue can lead to deanonymizing the user. The Common Vulnerabilities and Exposures project has assigned CVE-2011-2768 to this issue.

In addition to fixing the above mentioned issues, the updates to oldstable and stable fix a number of less critical issues (CVE-2011-2769 ). Please see the posting from the Tor blog for more information.

ID	Name	Product	Family	Severity
66144	Mandriva Linux Security Advisory : tor (MDVSA-2013:132)	Nessus	Mandriva Local Security Checks	medium
57654	GLSA-201201-12 : Tor: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high
56796	Fedora 16 : tor-0.2.2.34-1600.fc16 (2011-15208)	Nessus	Fedora Local Security Checks	medium
56720	Fedora 15 : tor-0.2.1.31-1500.fc15 (2011-15117)	Nessus	Fedora Local Security Checks	medium
56670	Debian DSA-2331-1 : tor - several vulnerabilities	Nessus	Debian Local Security Checks	medium

Detections

Analytics

CVE-2011-2769

medium

Tenable Plugins

medium

high

medium

medium

medium