Debian update for tor

Published: 2021-03-18

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2021-28089 CVE-2021-28090
CWE-ID	CWE-400 CWE-617
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	tor (Debian package) Operating systems & Components / Operating system package or component
Vendor	Debian

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Resource exhaustion

EUVDB-ID: #VU51541

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-2021-28089

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No

Description

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

The vulnerability exists due to application does not properly control consumption of internal resources when processing directory data. A remote attacker can force the Tor instance do consume huge amounts of CPU resources and perform a denial of service (DoS) attack.

Mitigation

Update tor package to version 0.3.5.14-1.

Vulnerable software versions

tor (Debian package): 0.3.5.3-alpha-1 - 0.3.5.12-1

External links

http://www.debian.org/security/2021/dsa-4871

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.

2) Reachable Assertion

EUVDB-ID: #VU51542