Information disclosure in Tor

1) Information disclosure

EUVDB-ID: #VU8851

Risk: Low

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-0380

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to obtain potentially sensitive information.

The vulnerability exists in the rend_service_intro_established() function in 'or/rendservice.c due to the system may log uninitialized stack contents when a certain hidden service error occurs while SafeLogging is disabled. A remote attacker can use an error message about the construction of an introduction point circuit and gain access to potentially sensitive information from uninitialized stack memory.

Mitigation

The vulnerability is addressed in the following versions: 0.2.8.15, 0.2.9.12, 0.3.0.11.

Vulnerable software versions

Tor: 0.2.8.1 - 0.3.2.1

External links

http://blog.torproject.org/new-tor-stable-releases-02815-02912-03011-fix-onion-service-security-iss...

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.