cvedb.io
CVE-2021-41115
MEDIUM · CVSS 4.3
EPSS exploitation probability: 0%
Published 2021-10-07T23:15:08.027 · Last modified 2026-06-17T04:07:54.053

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-rele

Affected products

zulip — zulip

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.