Vulnerability in Microsoft Exchange Server 2013 Cumulative Update 23

CVE-2021-31196

Microsoft Exchange Server Remote Code Execution Vulnerability

EPSS: 0.033 (87.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C.

Affected products

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-31196?
CVE-2021-31196 is a high-severity vulnerability in Microsoft Exchange Server 2013 Cumulative Update 23. CVSS score: 7.2/10. Published 2021-07-14.
How severe is CVE-2021-31196?
High severity. CVSS v3 base score is 7.2 out of 10.
Is CVE-2021-31196 known to be exploited?
Yes. CVE-2021-31196 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-08-21), indicating it is being actively exploited. 27 public proof-of-concept repositories are indexed.