Vulnerabilities > CVE-2021-41115 - Unspecified vulnerability in Zulip

CVSS 6.5 - MEDIUM

Attack vector

NETWORK

Attack complexity

LOW

Privileges required

LOW

Confidentiality impact

NONE

Integrity impact

NONE

Availability impact

HIGH

network

low complexity

zulip

NVD

Published: 2021-10-07

Updated: 2023-07-17

Summary

Zulip is an open source team chat server. In affected versions Zulip allows organization administrators on a server to configure "linkifiers" that automatically create links from messages that users send, detected via arbitrary regular expressions. Malicious organization administrators could subject the server to a denial-of-service via regular expression complexity attacks; most simply, by configuring a quadratic-time regular expression in a linkifier, and sending messages that exploited it. A regular expression attempted to parse the user-provided regexes to verify that they were safe from ReDoS -- this was both insufficient, as well as _itself_ subject to ReDoS if the organization administrator entered a sufficiently complex invalid regex. Affected users should [upgrade to the just-released Zulip 4.7](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-to-a-release), or [`main`](https://zulip.readthedocs.io/en/latest/production/upgrade-or-modify.html#upgrading-from-a-git-repository).

Vulnerable Configurations

Part	Description	Count
Application	Zulip Zulip Zulip - Zulip Zulip 0.7.1 Zulip Zulip 1.0.11 Zulip Zulip 1.0.12 Zulip Zulip 1.0.13 Zulip Zulip 1.0.14 Zulip Zulip 1.0.15 Zulip Zulip 1.0.16 Zulip Zulip 1.0.17 Zulip Zulip 1.0.18 Zulip Zulip 1.0.19 Zulip Zulip 1.0.20 Zulip Zulip 1.0.21 Zulip Zulip 1.0.22 Zulip Zulip 1.0.24 Zulip Zulip 1.0.25 Zulip Zulip 1.0.26 Zulip Zulip 1.0.27 Zulip Zulip 1.0.29 Zulip Zulip 1.3.0 Zulip Zulip 1.3.1 Zulip Zulip 1.3.2 Zulip Zulip 1.3.3 Zulip Zulip 1.3.4 Zulip Zulip 1.3.5 Zulip Zulip 1.3.6 Zulip Zulip 1.3.7 Zulip Zulip 1.3.8 Zulip Zulip 1.3.9 Zulip Zulip 1.3.10 Zulip Zulip 1.3.11 Zulip Zulip 1.3.12 Zulip Zulip 1.3.13 Zulip Zulip 1.4.0 Zulip Zulip 1.4.1 Zulip Zulip 1.4.2 Zulip Zulip 1.4.3 Zulip Zulip 1.5.0 Zulip Zulip 1.5.1 Zulip Zulip 1.5.2 Zulip Zulip 1.6.0 Zulip Zulip 1.7.0 Zulip Zulip 1.7.1 Zulip Zulip 1.7.2 Zulip Zulip 1.8.0 Zulip Zulip 1.8.1 Zulip Zulip 1.9.0 Zulip Zulip 1.9.1 Zulip Zulip 1.9.2 Zulip Zulip 2.0.0 Zulip Zulip 2.0.1 Zulip Zulip 2.0.2 Zulip Zulip 2.0.3 Zulip Zulip 2.0.4 Zulip Zulip 2.0.5 Zulip Zulip 2.0.6 Zulip Zulip 2.0.7 Zulip Zulip 2.0.8 Zulip Zulip 2.1.0 Zulip Zulip 2.1.1 Zulip Zulip 2.1.2 Zulip Zulip 2.1.3 Zulip Zulip 2.1.4 Zulip Zulip 2.1.5 Zulip Zulip 2.1.6 Zulip Zulip 2.1.7 Zulip Zulip 2.1.8 Zulip Zulip 2.1.33 Zulip Zulip 2.2 Zulip Zulip 2.3.35 Zulip Zulip 2.7.39 Zulip Zulip 3.0 Zulip Zulip 3.0.40 Zulip Zulip 3.1 Zulip Zulip 3.1.41 Zulip Zulip 3.2 Zulip Zulip 3.2.42 Zulip Zulip 3.3 Zulip Zulip 3.3.43 Zulip Zulip 3.4 Zulip Zulip 4.0 Zulip Zulip 4.1 Zulip Zulip 4.2 Zulip Zulip 4.3 Zulip Zulip 4.4 Zulip Zulip 4.5 Zulip Zulip 4.6	126

Summary

Vulnerable Configurations

References