Exploited vulnerability · CISA KEV

Is CVE-2021-26085 exploited? Yes: in CISA KEV since 28 Mar 2022

Gociux · Atlassian Confluence Server · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2021-26085, Atlassian Confluence Server Pre-Authorization Arbitrary File Read Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 28 Mar 2022, 237 days after it was published. It is known to be used in ransomware campaigns. It affects Atlassian Confluence Server. If you run it, CISA's required action is: Apply updates per vendor instructions.

What it is

Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a pre-authorization arbitrary file read vulnerability in the /s/ endpoint.

What to do

1. Check whether you run it. Look for Confluence Server in your asset inventory, including appliances and cloud images. Stack check lists every exploited Atlassian CVE at once.
2. Apply the fix. Apply updates per vendor instructions.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 3 Aug 2021.
4. Get told next time. Email alerts when CISA adds a CVE for Atlassian.

References

• nvd.nist.gov/vuln/detail/CVE-2021-26085

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in March 2022 · Atlassian scorecard · act-now radar.