Vulnerability identifier: #VU54231

Vulnerability risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-34550

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Tor
Client/Desktop applications / Web browsers

Vendor: tor.eff.org

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition during v3 onion service descriptor parsing. A remote attacker can create an onion service descriptor that would crash any client that tried to visit it.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Tor: 0.3.0 - 0.4.5.8

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External links
http://blog.torproject.org/node/2041

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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.