Multiple vulnerabilities in tor.eff Tor

Published: 2017-06-09 | Updated: 2020-07-18

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2017-0375 CVE-2017-0376
CWE-ID	CWE-617
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	Tor Client/Desktop applications / Web browsers
Vendor	tor.eff.org

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Reachable Assertion

EUVDB-ID: #VU31417

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2017-0375

CWE-ID: CWE-617 - Reachable Assertion

Exploit availability: No

Description

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

The hidden-service feature in Tor before 0.3.0.8 allows a denial of service (assertion failure and daemon exit) in the relay_send_end_cell_from_edge_ function via a malformed BEGIN cell.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Tor: 0.3.0.0 - 0.3.0.7

CPE2.3

External links

https://www.securityfocus.com/bid/99017
https://github.com/torproject/tor/commit/79b59a2dfcb68897ee89d98587d09e55f07e68d7
https://lists.torproject.org/pipermail/tor-announce/2017-June/000131.html
https://trac.torproject.org/projects/tor/ticket/22493

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) Reachable Assertion

EUVDB-ID: #VU31418