CVE-2021-44758
CVE-2021-44758 affecting package samba for versions less than 4.18.3-1
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
7.5
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.
- Record
CVE-2021-44758- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-476
- Updated
- 2026-11-02
CVE List
7.5
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.
- Record
CVE-2021-44758- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-476
- Updated
- 2026-11-02
EUVDEUVD-2021-31573
7.5
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.
- Record
EUVD-2021-31573- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVALPINE-CVE-2021-44758
7.5
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.
- Record
ALPINE-CVE-2021-44758- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-44859
7.5
CVE-2021-44758 affecting package samba for versions less than 4.18.3-1
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.
- Record
AZL-44859- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVBELL-CVE-2021-44758
7.5
CVE-2021-44758 does not affect BellSoft software
- Record
BELL-CVE-2021-44758- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 8 moreShow less
OSV
7.5
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.
- Record
CVE-2021-44758- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-44758
7.5
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.
- Record
DEBIAN-CVE-2021-44758- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-44758
7.5
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.
- Record
UBUNTU-CVE-2021-44758- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVMGASA-2022-0468 No score
Updated heimdal packages fix security vulnerability
Isaac Boukris reported that the Heimdal KDC before 7.7.1 does not apply delegation_not_allowed (aka not-delegated) user attributes for S4U2Self. Instead the forwardable flag is set even if the impersonated client has the not-delegated flag set. (CVE-2019-14870)
Joseph Sutton discovered that the Heimdal KDC before 7.7.1 does not check for missing sname in TGS-REQ (Ticket Granting Server Request) before dereferencing. An authenticated user could use this flaw to crash the KDC. (CVE-2021-3671)
It was discovered that Heimdal is prone to a NULL dereference in acceptors when the initial SPNEGO token has no acceptable mechanisms, which may result in denial of service for a server application that uses the Simple and Protected GSSAPI Negotiation Mechanism (SPNEGO). (CVE-2021-44758)
Evgeny Legerov reported that the DES and Triple-DES decryption routines in the Heimdal GSSAPI library before 7.7.1 were prone to buffer overflow on malloc() allocated memory when presented with a maliciously small packet. In addition, the Triple-DES and RC4 (arcfour) decryption routine were prone to non-constant time leaks, which could potentially yield to a leak of secret key material when using these ciphers. (CVE-2022-3437)
It was discovered that Heimdal's PKI certificate validation library before 7.7.1 can under some circumstances perform an out-of-bounds memory access when normalizing Unicode, which may result in denial of service. (CVE-2022-41916)
Greg Hudson discovered an integer multiplication overflow in the Privilege Attribute Certificate (PAC) parsing routine, which may result in denial of service for Heimdal KDCs and possibly Heimdal servers (e.g., via GSS-API) on 32-bit systems. (CVE-2022-42898)
Douglas Bagnall and the Heimdal maintainers independently discovered that Heimdal's ASN.1 compiler before 7.7.1 generates code that allows specially crafted DER encodings of CHOICEs to invoke the wrong free() function on the decoded structure upon decode error, which may result in remote code execution in the Heimdal KDC and possibly the Kerberos client, the X.509 library, and other components as well. (CVE-2022-44640)
- Record
MGASA-2022-0468- Updated
- 2026-11-02
OSVopenSUSE-SU-2023:0019-1 No score
Security update for libheimdal
This update for libheimdal fixes the following issues:
Update to version 7.8.0
- CVE-2022-42898 PAC parse integer overflows
- CVE-2022-3437 Overflows and non-constant time leaks in DES{,3} and arcfour
- CVE-2022-41916 Fix Unicode normalization read of 1 bytes past end of array
- CVE-2021-44758 A null pointer de-reference DoS in SPNEGO acceptors
- CVE-2021-3671 A null pointer de-reference when handling missing sname in TGS-REQ
- CVE-2022-44640 Heimdal KDC: invalid free in ASN.1 codec
- CVE-2019-14870: Validate client attributes in protocol-transition
- Record
openSUSE-SU-2023:0019-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2023:0020-1 No score
Security update for libheimdal
This update for libheimdal fixes the following issues:
Update to version 7.8.0
- CVE-2022-42898 PAC parse integer overflows
- CVE-2022-3437 Overflows and non-constant time leaks in DES{,3} and arcfour
- CVE-2022-41916 Fix Unicode normalization read of 1 bytes past end of array
- CVE-2021-44758 A null pointer de-reference DoS in SPNEGO acceptors
- CVE-2021-3671 A null pointer de-reference when handling missing sname in TGS-REQ
- CVE-2022-44640 Heimdal KDC: invalid free in ASN.1 codec
- CVE-2019-14870: Validate client attributes in protocol-transition
- Record
openSUSE-SU-2023:0020-1- Updated
- 2026-11-02
OSVopenSUSE-SU-2024:12580-1 No score
libasn1-8-7.8.0-1.1 on GA media
These are all security issues fixed in the libasn1-8-7.8.0-1.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:12580-1- Updated
- 2026-11-02
OSVUSN-5800-1 No score
heimdal vulnerabilities
It was discovered that Heimdal incorrectly handled certain SPNEGO tokens. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2021-44758)
Evgeny Legerov discovered that Heimdal incorrectly handled memory when performing certain DES decryption operations. A remote attacker could use this issue to cause a denial of service, or possibly execute arbitrary code. (CVE-2022-3437)
Greg Hudson discovered that Kerberos PAC implementation used in Heimdal incorrectly handled certain parsing operations. A remote attacker could use this issue to cause a denial of service, or possibly execute arbitrary code. (CVE-2022-42898)
It was discovered that Heimdal's KDC did not properly handle certain error conditions. A remote attacker could use this issue to cause a denial of service, or possibly execute arbitrary code. (CVE-2022-44640)
- Record
USN-5800-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
heimdalAlpine:v3.14 |
before 7.7.1-r0 | 7.7.1-r0 |
heimdalAlpine:v3.15 |
before 7.7.1-r0 | 7.7.1-r0 |
heimdalAlpine:v3.16 |
before 7.7.1-r0 | 7.7.1-r0 |
heimdalAlpine:v3.17 |
before 7.7.1-r0 | 7.7.1-r0 |
heimdalAlpine:v3.18 |
before 7.7.1-r0 | 7.7.1-r0 |
heimdalAlpine:v3.19 |
before 7.7.1-r0 | 7.7.1-r0 |
heimdalAlpine:v3.20 |
before 7.7.1-r0 | 7.7.1-r0 |
heimdalAlpine:v3.21 |
before 7.7.1-r0 | 7.7.1-r0 |
heimdalAlpine:v3.22 |
before 7.7.1-r0 | 7.7.1-r0 |
heimdalAlpine:v3.23 |
before 7.7.1-r0 | 7.7.1-r0 |
Show 25 moreShow less
| Package | Affected | Fixed |
|---|---|---|
heimdalAlpine:v3.24 |
before 7.7.1-r0 | 7.7.1-r0 |
sambaAzure Linux:3 |
before 4.18.3-1 | 4.18.3-1 |
heimdalDebian:12 |
before 7.8.git20221115.a6cf945+dfsg-1 | 7.8.git20221115.a6cf945+dfsg-1 |
heimdalDebian:13 |
before 7.8.git20221115.a6cf945+dfsg-1 | 7.8.git20221115.a6cf945+dfsg-1 |
heimdalDebian:14 |
before 7.8.git20221115.a6cf945+dfsg-1 | 7.8.git20221115.a6cf945+dfsg-1 |
heimdalDebian:10 From an advisory covering 7 CVEs |
before 7.5.0+dfsg-3+deb10u1, plus listed versions 7.5.0+dfsg-3 |
7.5.0+dfsg-3+deb10u1 |
heimdalDebian:11 From an advisory covering 6 CVEs |
before 7.7.0+dfsg-2+deb11u2, plus listed versions 7.7.0+dfsg-27.7.0+dfsg-2+deb11u1 |
7.7.0+dfsg-2+deb11u2 |
heimdalMageia:8 From an advisory covering 7 CVEs |
before 7.7.1-1.2.mga8 | 7.7.1-1.2.mga8 |
heimdalUbuntu:Pro:14.04:LTS |
before 1.6~git20131207+dfsg-1ubuntu1.2+esm3, plus listed versions 1.6~git20120403+dfsg1-3ubuntu0.11.6~git20120403+dfsg1-3ubuntu0.21.6~git20131207+dfsg-1ubuntu11.6~git20131207+dfsg-1ubuntu1.11.6~git20131207+dfsg-1ubuntu1.21.6~git20131207+dfsg-1ubuntu1.2+esm11.6~git20131207+dfsg-1ubuntu1.2+esm2 |
1.6~git20131207+dfsg-1ubuntu1.2+esm3 |
heimdalUbuntu:Pro:16.04:LTS |
before 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm3, plus listed versions 1.6~rc2+dfsg-10ubuntu11.7~git20150920+dfsg-4ubuntu11.7~git20150920+dfsg-4ubuntu1.16.04.11.7~git20150920+dfsg-4ubuntu1.16.04.1+esm11.7~git20150920+dfsg-4ubuntu1.16.04.1+esm2 |
1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm3 |
heimdalUbuntu:18.04:LTS |
before 7.5.0+dfsg-1ubuntu0.3, plus listed versions 7.4.0.dfsg.1-27.5.0+dfsg-17.5.0+dfsg-1ubuntu0.17.5.0+dfsg-1ubuntu0.2 |
7.5.0+dfsg-1ubuntu0.3 |
heimdalUbuntu:20.04:LTS |
before 7.7.0+dfsg-1ubuntu1.3, plus listed versions 7.5.0+dfsg-3build17.7.0+dfsg-17.7.0+dfsg-1ubuntu17.7.0+dfsg-1ubuntu1.17.7.0+dfsg-1ubuntu1.2 |
7.7.0+dfsg-1ubuntu1.3 |
heimdalUbuntu:22.04:LTS |
All versions, plus listed versions 7.7.0+dfsg-2ubuntu27.7.0+dfsg-3ubuntu1 |
None known |
heimdalUbuntu:24.04:LTS |
All versions, plus listed versions 7.8.git20221117.28daf24+dfsg-3ubuntu17.8.git20221117.28daf24+dfsg-3ubuntu27.8.git20221117.28daf24+dfsg-3ubuntu37.8.git20221117.28daf24+dfsg-3ubuntu47.8.git20221117.28daf24+dfsg-4ubuntu17.8.git20221117.28daf24+dfsg-5ubuntu27.8.git20221117.28daf24+dfsg-5ubuntu3 |
None known |
heimdalUbuntu:25.10 |
All versions, plus listed versions 7.8.git20221117.28daf24+dfsg-9ubuntu1 |
None known |
heimdalUbuntu:26.10 |
All versions, plus listed versions 7.8.git20221117.28daf24+dfsg-11ubuntu17.8.git20221117.28daf24+dfsg-12ubuntu17.8.git20240113.1b4565a+dfsg-1ubuntu17.8.git20240113.1b4565a+dfsg-1ubuntu27.8.git20240113.1b4565a+dfsg-2ubuntu1 |
None known |
heimdalUbuntu:26.04:LTS |
All versions, plus listed versions 7.8.git20221117.28daf24+dfsg-9ubuntu17.8.git20221117.28daf24+dfsg-10ubuntu17.8.git20221117.28daf24+dfsg-11ubuntu1 |
None known |
heimdalUbuntu:Pro:14.04:LTS From an advisory covering 4 CVEs |
before 1.6~git20131207+dfsg-1ubuntu1.2+esm3, plus listed versions 1.6~git20120403+dfsg1-3ubuntu0.11.6~git20120403+dfsg1-3ubuntu0.21.6~git20131207+dfsg-1ubuntu11.6~git20131207+dfsg-1ubuntu1.11.6~git20131207+dfsg-1ubuntu1.21.6~git20131207+dfsg-1ubuntu1.2+esm11.6~git20131207+dfsg-1ubuntu1.2+esm2 |
1.6~git20131207+dfsg-1ubuntu1.2+esm3 |
heimdalUbuntu:Pro:16.04:LTS From an advisory covering 4 CVEs |
before 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm3, plus listed versions 1.6~rc2+dfsg-10ubuntu11.7~git20150920+dfsg-4ubuntu11.7~git20150920+dfsg-4ubuntu1.16.04.11.7~git20150920+dfsg-4ubuntu1.16.04.1+esm11.7~git20150920+dfsg-4ubuntu1.16.04.1+esm2 |
1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm3 |
heimdalUbuntu:18.04:LTS From an advisory covering 4 CVEs |
before 7.5.0+dfsg-1ubuntu0.3, plus listed versions 7.4.0.dfsg.1-27.5.0+dfsg-17.5.0+dfsg-1ubuntu0.17.5.0+dfsg-1ubuntu0.2 |
7.5.0+dfsg-1ubuntu0.3 |
heimdalUbuntu:20.04:LTS From an advisory covering 4 CVEs |
before 7.7.0+dfsg-1ubuntu1.3, plus listed versions 7.5.0+dfsg-3build17.7.0+dfsg-17.7.0+dfsg-1ubuntu17.7.0+dfsg-1ubuntu1.17.7.0+dfsg-1ubuntu1.2 |
7.7.0+dfsg-1ubuntu1.3 |
libheimdalSUSE:Package Hub 15 SP4 From an advisory covering 7 CVEs |
before 7.8.0-bp154.2.4.1 | 7.8.0-bp154.2.4.1 |
libheimdalopenSUSE:Leap 15.4 From an advisory covering 7 CVEs |
before 7.8.0-bp154.2.4.1 | 7.8.0-bp154.2.4.1 |
libheimdalSUSE:Package Hub 15 SP3 From an advisory covering 7 CVEs |
before 7.8.0-bp153.2.4.1 | 7.8.0-bp153.2.4.1 |
libheimdalopenSUSE:Leap 15.3 From an advisory covering 7 CVEs |
before 7.8.0-bp153.2.4.1 | 7.8.0-bp153.2.4.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-44758 is a high vulnerability (CVSS 7.5) in Heimdal Project Heimdal, published November 22, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.33%, the 71st percentile. Fixed in heimdal 7.7.1-r0.
References
github.com/heimdal/heimdal/security/advisories/GHSA-69h9-669w-88xv
github.com/heimdal/heimdal/commit/f9ec7002cdd526ae84fbacbf153162e118f22580
security.gentoo.org/glsa/202310-06
security.alpinelinux.org/vuln/CVE-2021-44758
nvd.nist.gov/vuln/detail/CVE-2021-44758
docs.bell-sw.com/security/cves/CVE-2021-44758
Show 23 moreShow less
security-tracker.debian.org/tracker/CVE-2021-44758
advisories.mageia.org/MGASA-2022-0468.html
bugs.mageia.org/show_bug.cgi?id=31172
debian.org/security/2022/dsa-5286
debian.org/security/2022/dsa-5287
debian.org/lts/security/2022/dla-3206
github.com/heimdal/heimdal/security/advisories/GHSA-q77c-9qvp-qfw4
lists.fedoraproject.org/archives/list/[email protected]/thread/AYXWFESBZJMBNACFDHWWH7KETGKUXDPO
ubuntu.com/security/CVE-2021-44758
ubuntu.com/security/notices/USN-5800-1
cve.org/CVERecord?id=CVE-2021-44758
ubuntu.com/security/CVE-2022-3437
ubuntu.com/security/CVE-2022-42898
ubuntu.com/security/CVE-2022-44640
lists.opensuse.org/archives/list/[email protected]/thread/WO45C5LQHPOWEJHKWCXPWLI54XMTTYQP
suse.com/security/cve/CVE-2019-14870
suse.com/security/cve/CVE-2021-3671
suse.com/security/cve/CVE-2021-44758
suse.com/security/cve/CVE-2022-3437
suse.com/security/cve/CVE-2022-41916
suse.com/security/cve/CVE-2022-42898
suse.com/security/cve/CVE-2022-44640
lists.opensuse.org/archives/list/[email protected]/thread/VCW7YX6RG5EAFBRU3SLTXKN5NWVODXTH