CVE-2021-41115
4.3 · MEDIUMOverview
CVE-2021-41115 is a medium-severity vulnerability affecting zulip zulip. It was published on October 7, 2021 and has a CVSS 3.1 base score of 4.3 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.3, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
Technical 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#u
Remediation
Check the references section for vendor advisories and patches from zulip. Update zulip to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| zulip | zulip | >= 0, < 4.7 | Affected |
References
Frequently Asked Questions
What is CVE-2021-41115?
CVE-2021-41115 is a medium-severity vulnerability affecting zulip zulip. It was published on October 7, 2021 and has a CVSS 3.1 base score of 4.3 (MEDIUM).
How severe is CVE-2021-41115?
This vulnerability has a CVSS 3.1 base score of 4.3, rated MEDIUM. It can be exploited remotely over the network. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-41115?
Check the references section for vendor advisories and patches from zulip. Update zulip to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-41115?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-41115 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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