Memory leak in tor (Alpine package)

1) Memory leak

EUVDB-ID: #VU26506

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-2020-10593

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

Exploit availability: No

Description

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

The vulnerability exists due to memory leak in "circpad_setup_machine_on_circ" because a circuit-padding machine can be negotiated twice on the same circuit. A remote attacker can cause a denial of service condition on the target system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

tor (Alpine package): 0.3.5.8-r0 - 0.4.1.7-r0

CPE2.3

• cpe:2.3:o:alpine:tor_alpine_package:0.3.5.8-r0:*:*:*:*:alpine_linux:*:3.9
• cpe:2.3:o:alpine:tor_alpine_package:0.3.5.10-r0:*:*:*:*:alpine_linux:*:3.9
• cpe:2.3:o:alpine:tor_alpine_package:0.3.5.10-r1:*:*:*:*:alpine_linux:*:3.10

External links

https://git.alpinelinux.org/aports/commit/?id=f9e3cf1b2b6a6d6dcf9332ebca68b4e167276d48
https://git.alpinelinux.org/aports/commit/?id=d973662f3bf606989062d74e804a02b7c64a205a
https://git.alpinelinux.org/aports/commit/?id=2185d3b8d25a0f2e63d09e74b9c29683ef41bc2d

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.