Tor prior 0.2.4.26/0.2.5.11 Packets buf_pullup exceptional condition

Summaryinfo

A vulnerability was found in Tor. It has been declared as problematic. Impacted is the function buf_pullup of the component Packets Handler. The manipulation results in exceptional condition. This vulnerability is known as CVE-2015-2688. It is possible to launch the attack remotely. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Tor (Network Encryption Software). Affected is the function buf_pullup of the component Packets Handler. The manipulation with an unknown input leads to a exceptional condition vulnerability. CWE is classifying the issue as CWE-755. The product does not handle or incorrectly handles an exceptional condition. This is going to have an impact on availability. CVE summarizes:

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.

The weakness was published 04/22/2023 as 15083. The advisory is shared for download at trac.torproject.org. This vulnerability is traded as CVE-2015-2688 since 03/24/2015. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 11/27/2024).

The vulnerability scanner Nessus provides a plugin with the ID 82969 (Fedora 22 : tor-0.2.5.12-1.fc22 (2015-5890)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 167701 (OpenSuSE Security Update for tor (openSUSE-SU-2015:0600-1)).

Upgrading to version 0.2.4.26 or 0.2.5.11 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (82969). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Network Encryption Software

Name

• Tor

License

• open-source

CPE 2.3info

• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion