Known exploited vulnerability
CVE-2021-26084
The short answer
CVE-2021-26084 affects Atlassian Confluence Server and is rated critical (CVSS 9.8). CISA added it to the Known Exploited Vulnerabilities catalog on 2021-11-03: attackers are using it, so patch it first. The vendor has linked a patch.
What it is
In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an unauthenticated attacker to execute arbitrary code on a Confluence Server or Data Center instance. The affected versions are before version 6.13.23, from version 6.14.0 before 7.4.11, from version 7.5.0 before 7.11.6, and from version 7.12.0 before 7.12.5.
Weakness: CWE-917.
Severity
9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploited (CISA KEV)
Yes, since Nov 3, 2021
Federal due date Nov 17, 2021
EPSS, next 30 days
100%
Higher than 100% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
What CISA says to do
Apply updates per vendor instructions.
Affected products
Confluence Server, Confluence Data Center. NVD's record lists the exact affected versions.
References
- jira.atlassian.com/browse/CONFSERVER-67940 Issue TrackingPatchVendor Advisory
- jira.atlassian.com/browse/CONFSERVER-67940 Issue TrackingPatchVendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26084 US Government Resource
Questions
Is CVE-2021-26084 being exploited?
Yes. CISA added CVE-2021-26084 to its Known Exploited Vulnerabilities catalog on 2021-11-03, with a federal remediation due date of 2021-11-17. CISA lists it as used in ransomware campaigns.
How do I fix CVE-2021-26084?
CISA's required action: Apply updates per vendor instructions.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
Related
Latest CVEs this week
Critical and High CVEs from the last 7 days, with KEV and EPSS.
Exploited vulnerabilities by vendor
Every vendor in CISA's KEV catalog, with its count.
Atlassian exploited vulnerabilities
Everything CISA lists as exploited for Atlassian.
Vulnerability watch
A briefing and a fix pull request when an advisory hits your dependencies.
Know the day a CVE lands in your code
Connect a GitHub repository and ZeusQA checks its dependencies daily, briefs each advisory and opens the fix. Three test runs free, no card.