kernel: nfsd4: fix null dereference creating nfsv4 callback client
Published Oct 30, 2009
7.8
HIGHCVSS 2.0
EPSS 3.47%
Description
The lookup_cb_cred function in fs/nfsd/nfs4callback.c in the nfsd4 subsystem in the Linux kernel before 2.6.31.2 attempts to access a credentials cache even when a client specifies the AUTH_NULL authentication flavor, which allows remote attackers to cause a denial of service (NULL pointer dereference and system crash) via an NFSv4 mount request.
Affected products
No data.
- ≤ 2.6.31.1
- 2.6.0
- 2.6.1
- 2.6.2
- 2.6.3
- 2.6.4
- 2.6.5
- 2.6.6
- 2.6.7
- 2.6.8
- 2.6.8.1
- 2.6.9
- 2.6.10
- 2.6.11
- 2.6.11.1
- 2.6.11.2
- 2.6.11.3
- 2.6.11.4
- 2.6.11.5
- 2.6.11.6
- 2.6.11.7
- 2.6.11.8
- 2.6.11.9
- 2.6.11.10
- 2.6.11.11
- 2.6.11.12
- 2.6.12
- 2.6.12.1
- 2.6.12.2
- 2.6.12.3
- 2.6.12.4
- 2.6.12.5
- 2.6.12.6
- 2.6.13
- 2.6.13.1
- 2.6.13.2
- 2.6.13.3
- 2.6.13.4
- 2.6.13.5
- 2.6.14
- 2.6.14.1
- 2.6.14.2
- 2.6.14.3
- 2.6.14.4
- 2.6.14.5
- 2.6.14.6
- 2.6.14.7
- 2.6.15
- 2.6.15.1
- 2.6.15.2
- 2.6.15.3
- 2.6.15.4
- 2.6.15.5
- 2.6.15.6
- 2.6.15.7
- 2.6.16
- 2.6.16.1
- 2.6.16.2
- 2.6.16.3
- 2.6.16.4
- 2.6.16.5
- 2.6.16.6
- 2.6.16.7
- 2.6.16.8
- 2.6.16.9
- 2.6.16.10
- 2.6.16.11
- 2.6.16.12
- 2.6.16.13
- 2.6.16.14
- 2.6.16.15
- 2.6.16.16
- 2.6.16.17
- 2.6.16.18
- 2.6.16.19
- 2.6.16.20
- 2.6.16.21
- 2.6.16.22
- 2.6.16.23
- 2.6.16.24
- 2.6.16.25
- 2.6.16.26
- 2.6.16.27
- 2.6.16.28
- 2.6.16.29
- 2.6.16.30
- 2.6.16.31
- 2.6.16.32
- 2.6.16.33
- 2.6.16.34
- 2.6.16.35
- 2.6.16.36
- 2.6.16.37
- 2.6.16.38
- 2.6.16.39
- 2.6.16.40
- 2.6.16.41
- 2.6.16.42
- 2.6.16.43
- 2.6.16.44
- 2.6.16.45
- 2.6.16.46
- 2.6.16.47
- 2.6.16.48
- 2.6.16.49
- 2.6.16.50
- 2.6.16.51
- 2.6.16.52
- 2.6.16.53
- 2.6.16.54
- 2.6.16.55
- 2.6.16.56
- 2.6.16.57
- 2.6.16.58
- 2.6.16.59
- 2.6.16.60
- 2.6.16.61
- 2.6.16.62
- 2.6.17
- 2.6.17.1
- 2.6.17.2
- 2.6.17.3
- 2.6.17.4
- 2.6.17.5
- 2.6.17.6
- 2.6.17.7
- 2.6.17.8
- 2.6.17.9
- 2.6.17.10
- 2.6.17.11
- 2.6.17.12
- 2.6.17.13
- 2.6.17.14
- 2.6.18
- 2.6.18.1
- 2.6.18.2
- 2.6.18.3
- 2.6.18.4
- 2.6.18.5
- 2.6.18.6
- 2.6.18.7
- 2.6.18.8
- 2.6.19
- 2.6.19.1
- 2.6.19.2
- 2.6.19.3
- 2.6.19.4
- 2.6.19.5
- 2.6.19.6
- 2.6.19.7
- 2.6.20
- 2.6.20.1
- 2.6.20.2
- 2.6.20.3
- 2.6.20.4
- 2.6.20.5
- 2.6.20.6
- 2.6.20.7
- 2.6.20.8
- 2.6.20.9
- 2.6.20.10
- 2.6.20.11
- 2.6.20.12
- 2.6.20.13
- 2.6.20.14
- 2.6.20.15
- 2.6.20.16
- 2.6.20.17
- 2.6.20.18
- 2.6.20.19
- 2.6.20.20
- 2.6.20.21
- 2.6.21
- 2.6.21.1
- 2.6.21.2
- 2.6.21.3
- 2.6.21.4
- 2.6.21.5
- 2.6.21.6
- 2.6.21.7
- 2.6.22
- 2.6.22.1
- 2.6.22.2
- 2.6.22.3
- 2.6.22.4
- 2.6.22.5
- 2.6.22.6
- 2.6.22.7
- 2.6.22.8
- 2.6.22.9
- 2.6.22.10
- 2.6.22.11
- 2.6.22.12
- 2.6.22.13
- 2.6.22.14
- 2.6.22.15
- 2.6.22.16
- 2.6.22.17
- 2.6.22.18
- 2.6.22.19
- 2.6.23
- 2.6.23.1
- 2.6.23.2
- 2.6.23.3
- 2.6.23.4
- 2.6.23.5
- 2.6.23.6
- 2.6.23.7
- 2.6.23.8
- 2.6.23.9
- 2.6.23.10
- 2.6.23.11
- 2.6.23.12
- 2.6.23.13
- 2.6.23.14
- 2.6.23.15
- 2.6.23.16
- 2.6.23.17
- 2.6.24
- 2.6.24.1
- 2.6.24.2
- 2.6.24.3
- 2.6.24.4
- 2.6.24.5
- 2.6.24.6
- 2.6.24.7
- 2.6.25
- 2.6.25.1
- 2.6.25.2
- 2.6.25.3
- 2.6.25.4
- 2.6.25.5
- 2.6.25.6
- 2.6.25.7
- 2.6.25.8
- 2.6.25.9
- 2.6.25.10
- 2.6.25.11
- 2.6.25.12
- 2.6.25.13
- 2.6.25.14
- 2.6.25.15
- 2.6.25.16
- 2.6.25.17
- 2.6.25.18
- 2.6.25.19
- 2.6.25.20
- 2.6.26
- 2.6.26.1
- 2.6.26.2
- 2.6.26.3
- 2.6.26.4
- 2.6.26.5
- 2.6.26.6
- 2.6.26.7
- 2.6.26.8
- 2.6.27
- 2.6.27.1
- 2.6.27.2
- 2.6.27.3
- 2.6.27.4
- 2.6.27.5
- 2.6.27.6
- 2.6.27.7
- 2.6.27.8
- 2.6.27.9
- 2.6.27.10
- 2.6.27.11
- 2.6.27.12
- 2.6.27.13
- 2.6.27.14
- 2.6.27.15
- 2.6.27.16
- 2.6.27.17
- 2.6.27.18
- 2.6.27.19
- 2.6.27.20
- 2.6.27.21
- 2.6.27.22
- 2.6.27.23
- 2.6.27.24
- 2.6.27.25
- 2.6.27.26
- 2.6.27.27
- 2.6.27.28
- 2.6.27.29
- 2.6.27.30
- 2.6.27.31
- 2.6.28
- 2.6.28.1
- 2.6.28.2
- 2.6.28.3
- 2.6.28.4
- 2.6.28.5
- 2.6.28.6
- 2.6.28.7
- 2.6.28.8
- 2.6.28.9
- 2.6.28.10
- 2.6.29
- 2.6.29.1
- 2.6.29.2
- 2.6.29.3
- 2.6.29.4
- 2.6.29.5
- 2.6.29.6
- 2.6.30
- 2.6.30.1
- 2.6.30.2
- 2.6.30.3
- 2.6.30.4
- 2.6.30.5
- 2.6.30.6
- 2.6.30.7
- 2.6.30.8
- 2.6.30.9
- 2.6.31
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
Red Hat statement
Not vulnerable. This issue did not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 3, 4, 5, or Red Hat Enterprise MRG. Those versions do not include the upstream patch that introduced this vulnerability.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
No CVSS v3.0 score for this CVE.
AV:N/AC:L/Au:N/C:N/I:N/A:C
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.47% (0.03474) | 88.70th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.47% (0.03474) | 87.52th | v5 (v2026.06.15) |
| Mar 17, 2025 | 1.41% (0.01408) | 79.16th | v4 (v2025.03.14) |
| Dec 12, 2024 | 4.35% (0.04348) | 92.66th | v3 (v2023.03.01) |
| Mar 7, 2023 | 4.35% (0.04348) | 91.04th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.41% (0.01408) | 72.89th | v2 (v2022.01.01) |
| Feb 13, 2023 | 1.41% (0.01408) | 72.37th | v2 (v2022.01.01) |
| Feb 3, 2023 | 1.97% (0.01974) | 78.39th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.41% (0.01408) | 70.87th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.41% (0.01408) | 49.94th | v2 (v2022.01.01) |
References (11)
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=80fc015bdfe1f5b870c1e1ee02d78e709523fee7 x_refsource_CONFIRM
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=886e3b7fe6054230c89ae078a09565ed183ecc73 x_refsource_CONFIRM
- http://marc.info/?l=oss-security&m=125618753029631&w=2 mailing-listx_refsource_MLIST
- http://marc.info/?l=oss-security&m=125624036516377&w=2 mailing-listx_refsource_MLIST
- http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.31.2 x_refsource_CONFIRM
- http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.32-rc1 x_refsource_CONFIRM
- http://www.ubuntu.com/usn/usn-864-1 vendor-advisoryx_refsource_UBUNTU
- https://access.redhat.com/security/cve/CVE-2009-3623 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=530269 x_refsource_CONFIRMIssue Tracking
- https://nvd.nist.gov/vuln/detail/CVE-2009-3623
- https://www.cve.org/CVERecord?id=CVE-2009-3623
| Link | Providers | Tags |
|---|---|---|
| http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=80fc015bdfe1f5b870c1e1ee02d78e709523fee7 | x_refsource_CONFIRM | |
| http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=886e3b7fe6054230c89ae078a09565ed183ecc73 | x_refsource_CONFIRM | |
| http://marc.info/?l=oss-security&m=125618753029631&w=2 | mailing-listx_refsource_MLIST | |
| http://marc.info/?l=oss-security&m=125624036516377&w=2 | mailing-listx_refsource_MLIST | |
| http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.31.2 | x_refsource_CONFIRM | |
| http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.32-rc1 | x_refsource_CONFIRM | |
| http://www.ubuntu.com/usn/usn-864-1 | vendor-advisoryx_refsource_UBUNTU | |
| https://access.redhat.com/security/cve/CVE-2009-3623 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=530269 | x_refsource_CONFIRMIssue Tracking | |
| https://nvd.nist.gov/vuln/detail/CVE-2009-3623 | ||
| https://www.cve.org/CVERecord?id=CVE-2009-3623 |
Change history (0)
No recorded changes yet.