PT-2021-22099 · Tor+4 · Tor+4

Hdevalence

+1

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Published

2021-08-17

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Updated

2025-05-12

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CVE-2021-38385

CVSS v3.1

7.5

High

VectorAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Tor versions prior to 0.3.5.16 Tor versions prior to 0.4.5.10 Tor versions prior to 0.4.6.7
Description The issue is related to how Tor handles the relationship between batch-signature verification and single-signature verification, leading to a remote assertion failure. This can be used to initiate a denial of service. The problem occurs due to a discrepancy in the behavior of code for verifying digital signatures individually and in batch mode.
Recommendations For versions prior to 0.3.5.16, update to version 0.3.5.16 or later. For versions prior to 0.4.5.10, update to version 0.4.5.10 or later. For versions prior to 0.4.6.7, update to version 0.4.6.7 or later.

Exploit

Fix

Assertion Failure

Weakness Enumeration

Related Identifiers

ALT-PU-2021-2569
ALT-PU-2021-3213
ALT-PU-2025-6362
CVE-2021-38385
DSA-4961-1
MGASA-2021-0426
OPENSUSE-SU-2021:1169-1
OPENSUSE-SU-2021:1178-1
OPENSUSE-SU-2021:1192-1
OPENSUSE-SU-2021_1169-1
OPENSUSE-SU-2024:11469-1
USN-5036-1

Affected Products

Alt Linux
Linuxmint
Suse
Tor
Ubuntu