How severe is CVE-2021-37750?

CVE-2021-37750 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-37750 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-37750?

CVE-2021-37750 primarily affects Mit Kerberos 5. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-37750?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-37750 published?

CVE-2021-37750 was published on 2021-08-23 and last updated on 2026-06-17.

CVE-2021-37750

CVE-2021-37750 is a medium-severity vulnerability in Mit Kerberos 5 with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Mit Kerberos 5
Published: 2021-08-23
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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 inner body that lacks a server field.
How severe is CVE-2021-37750?: CVE-2021-37750 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-37750 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37750?: CVE-2021-37750 primarily affects Mit Kerberos 5. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-37750?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-37750 published?: CVE-2021-37750 was published on 2021-08-23 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:mit:kerberos_5:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8r13:14338:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_cloud_native_core_network_slice_selection_function:22.1.0:*:*:*:*:*:*:*

More vulnerabilities in Mit Kerberos 5

CVE-2011-0285 — Critical (CVSS 10.0): The process_chpw_request function in schpw.c in the password-changing functionality in kadmind in MIT Kerberos 5 (aka…
CVE-2009-4212 — Critical (CVSS 10.0): Multiple integer underflows in the (1) AES and (2) RC4 decryption functionality in the crypto library in MIT Kerberos 5…
CVE-2009-0846 — Critical (CVSS 10.0): The asn1_decode_generaltime function in lib/krb5/asn.1/asn1_decode.c in the ASN.1 GeneralizedTime decoder in MIT…
CVE-2008-0947 — Critical (CVSS 10.0): Buffer overflow in the RPC library used by libgssrpc and kadmind in MIT Kerberos 5 (krb5) 1.4 through 1.6.3 allows…
CVE-2007-5902 — Critical (CVSS 10.0): Integer overflow in the svcauth_gss_get_principal function in lib/rpc/svc_auth_gss.c in MIT Kerberos 5 (krb5) allows…
CVE-2007-4743 — Critical (CVSS 10.0): The original patch for CVE-2007-3999 in svc_auth_gss.c in the RPCSEC_GSS RPC library in MIT Kerberos 5 (krb5) 1.4…

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Other CWE-476 (NULL Pointer Dereference) vulnerabilities

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CVE-2026-46195 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: smb: client: validate dacloffset before building…
CVE-2026-31657 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by…
CVE-2026-31436 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: fix possible wrong descriptor…

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