CVE-2021-41115

Sažetak

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).

Reference

CVSS

Base:	4.0
Impact:	2.9
Exploitability:	8.0

Pristup

Vektor	Složenost	Autentikacija
NETWORK	LOW	SINGLE

Impact

Povjerljivost	Cjelovitost	Dostupnost
NONE	NONE	PARTIAL

CVSS vektor

AV:N/AC:L/Au:S/C:N/I:N/A:P

Zadnje važnije ažuriranje

17-07-2023 - 15:18

Objavljeno

07-10-2021 - 23:15