Description


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).

Related CPE's


Vulnerable

Weaknesses



CWE-1333


CWE-1333CWE-400

CVSS impact metrics


CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

6.5 · Medium

  • CVSS V3.1

  • CVSS V3.0

  • CVSS V2.0

Information


Source identifier

[email protected]

Vulnerability status

Analyzed

Published

2021-10-07T23:15:08.027

3 years ago

Last modified

2023-07-17T15:18:03.750

1 year ago