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Vulnerabilities

Vulnerability · CVE-2021-37750

The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.5 and 1.19.x before 1.19.3 has a NULL pointer dereference in kdc/do_tgs_req.c via a FAST inn…

Published Aug 23, 2021 · catalog updated Oct 14, 2026 · kerberos 5

Check if you run it

No confirmed exploitation is on record for CVE-2021-37750. EPSS is 2.50%. Act only if a listed version of kerberos 5 is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium6.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
2.50%
Remediation
Advisory link
Affected products
cpe debian/debian linux · cpe fedoraproject/fedora · cpe mit/kerberos 5 · cpe oracle/communications cloud native core network slice selection function · cpe starwindsoftware/starwind virtual san

The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.5 and 1.19.x before 1.19.3 has a NULL pointer dereference in kdc/do_tgs_req.c via a FAST inner body that lacks a server field.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe debian/debian linux9.0
  • cpe fedoraproject/fedora33
  • cpe mit/kerberos 5version unspecified
  • cpe oracle/communications cloud native core network slice selection function22.1.0
  • cpe starwindsoftware/starwind virtual sanv8r13

How to fix CVE-2021-37750

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2021-37750. EPSS is 2.50%. Act only if a listed version of kerberos 5 is installed.

Which versions are affected?

Compare what you have installed with debian/debian linux 9.0; oracle/communications cloud native core network slice selection function 22.1.0; starwindsoftware/starwind virtual san v8r13. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-476: NULL Pointer Dereference. EPSS 2.50%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Aug 23, 2021 · NIST NVD

    Detected

    The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.5 and 1.19.x before 1.19.3 has a NULL pointer dereference in kdc/do_tgs_req.c via a FAST inner body that lacks a server field.

  2. Oct 14, 2026 · NIST NVD

    Updated

    The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.5 and 1.19.x before 1.19.3 has a NULL pointer dereference in kdc/do_tgs_req.c via a FAST inner body that lacks a server field.

Sources

  • CVE.orgVulnerability recordCVE-2021-37750

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-37750

    30-day exploitation probability 2.5%

    first.org
  • NIST NVDVulnerability recordCVE-2021-37750

    The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.5 and 1.19.x before 1.19.3 has a NULL pointer dereference in kdc/do_tgs_req.c via a FAST inner body that lacks a server field.

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.