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CVE-2021-44758

25
FAUCET Score

CVE-2021-44758 is a NULL pointer dereference vulnerability affecting Heimdal versions prior to 7.7.1. An unauthenticated attacker can remotely trigger this flaw by sending a specially crafted SPNEGO acceptor request, leading to a denial-of-service condition. With a CVSS score of 7.5 (High), this vulnerability is easily exploitable over the network with low attack complexity and no user interaction required. There is currently no public exploit code available, nor is there any evidence of active exploitation or significant community discussion surrounding this CVE.

Impacted Technologies

VendorProductVersion(s)CPE
< 7.7.1CPE matchmatch criteria
cpe:2.3:a:heimdal_project:heimdal:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.5HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
3.6
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.22%
Probability of exploitation in next 30 days
EPSS Percentile
65.6%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0122 is in the 45th percentile among its peer group of 51,551 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (9)

github_advisorypatch availablevia nvd_reference
View patch
microsoftpatch availablevia msrc
Product: 18503-16820Fixed in: 7.7.1-1
microsoftpatch availablevia msrc
Product: 16864-17084Fixed in: 4.18.3-1
microsoftpatch availablevia msrc
Product: cm1 heimdal 7.7.1-1 on CBL Mariner 1.0Fixed in: 7.7.1-1
microsoftpatch availablevia msrc
Product: azl3 samba 4.18.3-1 on Azure Linux 3.0Fixed in: 4.18.3-1
microsoftpatch availablevia msrc
Product: Azure Linux 3.0 x64Fixed in: 4.18.3-1
microsoftpatch availablevia msrc
Product: Azure Linux 3.0 ARMFixed in: 4.18.3-1
microsoftpatch availablevia msrc
Product: CBL Mariner 1.0 x64Fixed in: 7.7.1-1
microsoftpatch availablevia msrc
Product: CBL Mariner 1.0 ARMFixed in: 7.7.1-1

Vendor Advisories (2)

microsoft2024-Oct/CVE-2021-44758

CVE-2021-44758

Oct 8, 2024
microsoft2022-Dec/CVE-2021-44758Important

Heimdal before 7.7.1 allows attackers to cause a NULL pointer dereference in a SPNEGO acceptor via a preferred_mech_type of GSS_C_NO_OID and a nonzero initial_response value to send_accept.

Dec 13, 2022

References

github.com / heimdal/heimdal/commit/f9ec7002cdd526ae84fbacbf153162e118f22580
PatchThird Party Advisory
github.com / heimdal/heimdal/security/advisories/GHSA-69h9-669w-88xv
Third Party Advisory
security.gentoo.org / glsa/202310-06