Vulnerability identifier: #VU34151

Vulnerability 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-2020-15572

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Tor
Client/Desktop applications / Web browsers

Vendor: tor.eff.org

Description

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

Tor before 0.4.3.6 has an out-of-bounds memory access that allows a remote denial-of-service (crash) attack against Tor instances built to use Mozilla Network Security Services (NSS), aka TROVE-2020-001.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Tor: 0.4.4.0 - 0.4.4.1

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External links
http://blog.torproject.org/new-release-tor-03511-0428-0436-security-fixes
http://gitlab.torproject.org/tpo/core/tor/-/issues/33119
http://trac.torproject.org/projects/tor/wiki/TROVE

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Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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