CVE-2021-27889

Public Exploit

Description

Cross-site Scripting (XSS) vulnerability in MyBB before 1.8.26 via Nested Auto URL when parsing messages.

Category

6.1
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 2.24% Top 20%
Third-Party Advisory packetstormsecurity.com Third-Party Advisory sonarsource.com Third-Party Advisory github.com
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://github.com/mybb/mybb/security/advisories/GHSA-xhj7-3349-mqcm third party advisory patch
http://packetstormsecurity.com/files/161908/MyBB-1.8.25-Remote-Command-Execution.html exploit vdb entry third party advisory
https://blog.sonarsource.com/mybb-remote-code-execution-chain third party advisory exploit

Frequently Asked Questions

What is the severity of CVE-2021-27889?
CVE-2021-27889 has been scored as a medium severity vulnerability.
How to fix CVE-2021-27889?
To fix CVE-2021-27889, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-27889 being actively exploited in the wild?
It is possible that CVE-2021-27889 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~2% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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