Known exploited vulnerability
CVE-2021-31196
The short answer
CVE-2021-31196 affects Microsoft Microsoft Exchange Server 2013 Cumulative Update 23 and is rated high (CVSS 7.2). CISA added it to the Known Exploited Vulnerabilities catalog on 2024-08-21: attackers are using it, so patch it first. The vendor has linked a patch.
What it is
Microsoft Exchange Server Remote Code Execution Vulnerability
Severity
7.2 high
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Exploited (CISA KEV)
Yes, since Aug 21, 2024
Federal due date Sep 11, 2024
EPSS, next 30 days
54%
Higher than 99% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
What CISA says to do
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected products
Microsoft Exchange Server 2013 Cumulative Update 23, Microsoft Exchange Server 2016 Cumulative Update 20, Microsoft Exchange Server 2016 Cumulative Update 21, Microsoft Exchange Server 2019 Cumulative Update 10, Microsoft Exchange Server 2019 Cumulative Update 9. NVD's record lists the exact affected versions.
References
- msrc.microsoft.com/update-guide/vulnerability/CVE-2021-31196 PatchVendor Advisory
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31196 PatchVendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-31196 US Government Resource
Questions
Is CVE-2021-31196 being exploited?
Yes. CISA added CVE-2021-31196 to its Known Exploited Vulnerabilities catalog on 2024-08-21, with a federal remediation due date of 2024-09-11.
How do I fix CVE-2021-31196?
CISA's required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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