Multiple vulnerabilities in tor.eff Tor

Published: 2020-01-24 | Updated: 2020-07-17

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2015-2688 CVE-2015-2689
CWE-ID	CWE-20
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	Tor Client/Desktop applications / Web browsers
Vendor	tor.eff.org

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Improper Handling of Exceptional Conditions

EUVDB-ID: #VU30428

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2015-2688

CWE-ID: N/A

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

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.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Tor: 0.2.5.1 - 0.2.5.10

External links

http://lists.torproject.org/pipermail/tor-talk/2015-March/037281.html
http://trac.torproject.org/projects/tor/ticket/15083

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Input validation error

EUVDB-ID: #VU30429