CVE-2021-41115

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, or main.

Affected Software

VendorProductVersion RangeStatus
zulipzulip< 4.7affected

Weaknesses

  • CWE-400: CWE-400: Uncontrolled Resource Consumption
  • CWE-1333: CWE-1333: Inefficient Regular Expression Complexity

ADP Enrichment

CVE Program Container

Additional References

References