CVE-2021-44758: 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…
Noroxi assessment
Priority: Monitor (action score 30/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 1.3% (FIRST EPSS); higher than 71.3% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to CISA the attack is automatable: targets can be found by mass scanning.
- Fixed version: Azure Linux 3.0 ARM 4.18.3-1; Azure Linux 3.0 x64 4.18.3-1; CBL Mariner 1.0 ARM 7.7.1-1.
Low priority for now. Upgrade to Azure Linux 3.0 ARM 4.18.3-1; Azure Linux 3.0 x64 4.18.3-1; CBL Mariner 1.0 ARM 7.7.1-1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- Published
- Dec 26, 2022
- Updated
- Jun 17, 2026
- EPSS
- 1.3% · 71th percentile
- CWE
- CWE-476
Report tools
Action score
30
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| heimdal project | heimdal | cpe:2.3:a:heimdal_project:heimdal |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- heimdal project heimdalbefore 7.7.1
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.14 | heimdal | before 7.7.1-r0 | 7.7.1-r0 |
| Debian:10 | heimdal | before 7.5.0+dfsg-3+deb10u1 | 7.5.0+dfsg-3+deb10u1 |
| Debian:11 | heimdal | before 7.7.0+dfsg-2+deb11u2 | 7.7.0+dfsg-2+deb11u2 |
| Debian:12 | heimdal | before 7.8.git20221115.a6cf945+dfsg-1 | 7.8.git20221115.a6cf945+dfsg-1 |
| openSUSE:Leap 15.3 | libheimdal | before 7.8.0-bp153.2.4.1 | 7.8.0-bp153.2.4.1 |
| openSUSE:Leap 15.4 | libheimdal | before 7.8.0-bp154.2.4.1 | 7.8.0-bp154.2.4.1 |
| SUSE:Package Hub 15 SP3 | libheimdal | before 7.8.0-bp153.2.4.1 | 7.8.0-bp153.2.4.1 |
| SUSE:Package Hub 15 SP4 | libheimdal | before 7.8.0-bp154.2.4.1 | 7.8.0-bp154.2.4.1 |
Same product
heimdal project: all recordsOther highest-scoring records for the same primary product.
- CVE-2004-0434k5admind (kadmind) for Heimdal allows remote attackers to execute arbitrary code via a Kerberos 4 compatibility administration request…41Plan
- CVE-2022-44640Heimdal before 7.7.1 allows remote attackers to execute arbitrary code because of an invalid free in the ASN.1 codec used by the Key…40Plan
- CVE-2017-11103Heimdal before 7.4 allows remote attackers to impersonate services with Orpheus' Lyre attacks because it obtains service-principal names in…34Monitor
Published before and after this one in the same product
- ← EarlierCVE-2019-12098May 15, 2019 · In the client side of Heimdal before 7.6.0, failure to verify anonymous PKINIT PA-PKINIT-KX key exchange permits a man-in-the-middle attack.30Monitor
- ← EarlierCVE-2022-41916Nov 15, 2022 · Read one byte past a buffer when normalizing Unicode30Monitor
- Later →CVE-2022-45142Mar 6, 2023 · The fix for CVE-2022-3437 included changing memcmp to be constant time and a workaround for a compiler bug by adding "!= 0" comparisons to…30Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Azure Linux 3.0 ARM | 4.18.3-1 · samba | Microsoft (MSRC) |
| Azure Linux 3.0 x64 | 4.18.3-1 · samba | Microsoft (MSRC) |
| CBL Mariner 1.0 ARM | 7.7.1-1 · heimdal | Microsoft (MSRC) |
| CBL Mariner 1.0 x64 | 7.7.1-1 · heimdal | Microsoft (MSRC) |
| alpine:heimdal | 7.7.1-r0 · Alpine:v3.14 | Package registry (OSV) |
| debian:heimdal | 7.8.git20221115.a6cf945+dfsg-1 · Debian:12 | Package registry (OSV) |
| opensuse:libheimdal | 7.8.0-bp154.2.4.1 · openSUSE:Leap 15.4 | Package registry (OSV) |
| suse:libheimdal | 7.8.0-bp154.2.4.1 · SUSE:Package Hub 15 SP4 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Not on record for this CVE: EPSS history · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-476 · NULL Pointer DereferenceCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.