kernel: tun/tap: Fix crashes if open() /dev/net/tun and then poll() it
Published Jul 20, 2009
6.9
MEDIUMCVSS 2.0
EPSS 1.52%
Description
The tun_chr_poll function in drivers/net/tun.c in the tun subsystem in the Linux kernel 2.6.30 and 2.6.30.1, when the -fno-delete-null-pointer-checks gcc option is omitted, allows local users to gain privileges via vectors involving a NULL pointer dereference and an mmap of /dev/net/tun, a different vulnerability than CVE-2009-1894.
Affected products
No data.
- 2.6.30
- 2.6.30
- 2.6.30
- 2.6.30
- 2.6.30
- 2.6.30
- 2.6.30
- 2.6.30
- 2.6.30.1
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
Red Hat statement
The flaw only affects the Red Hat Enterprise Linux 5.4 beta kernel, which includes a backport of the upstream bug fix introducing this flaw (git commit 33dccbb0). This issue did not affect the final released Red Hat Enterprise Linux 5.4 kernel. It is also possible to mitigate this flaw by ensuring that the permissions for /dev/net/tun is restricted to root only. This issue does not affect any other released kernel in any Red Hat product.
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:L/AC:M/Au:N/C:C/I:C/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 3, 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 (13 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 3, 2026 | 1.52% (0.01521) | 73.71th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.52% (0.01521) | 71.22th | v5 (v2026.06.15) |
| Feb 4, 2026 | 1.76% (0.01757) | 82.20th | v4 (v2025.03.14) |
| Sep 18, 2025 | 2.92% (0.02918) | 85.89th | v4 (v2025.03.14) |
| Mar 30, 2025 | 3.93% (0.03927) | 87.24th | v4 (v2025.03.14) |
| Mar 29, 2025 | 2.13% (0.02130) | 73.60th | v4 (v2025.03.14) |
| Mar 17, 2025 | 4.69% (0.04691) | 88.62th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.04% (0.00042) | 5.10th | v3 (v2023.03.01) |
| Mar 13, 2023 | 0.04% (0.00042) | 5.69th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.04% (0.00042) | 0.50th | v3 (v2023.03.01) |
| Mar 6, 2023 | 3.22% (0.03220) | 84.21th | v2 (v2022.01.01) |
| Apr 1, 2022 | 3.22% (0.03220) | 82.61th | v2 (v2022.01.01) |
| Feb 4, 2022 | 3.22% (0.03220) | 65.30th | v2 (v2022.01.01) |
References (16)
- http://archives.neohapsis.com/archives/fulldisclosure/2009-07/0241.html mailing-listx_refsource_FULLDISC
- http://archives.neohapsis.com/archives/fulldisclosure/2009-07/0246.html mailing-listx_refsource_FULLDISC
- http://article.gmane.org/gmane.linux.network/124939 mailing-listx_refsource_MLIST
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=3c8a9c63d5fd738c261bd0ceece04d9c8357ca13 x_refsource_CONFIRM
- http://grsecurity.net/~spender/cheddar_bay.tgz x_refsource_MISCPatch
- http://isc.sans.org/diary.html?storyid=6820 x_refsource_MISCExploit
- http://lkml.org/lkml/2009/7/6/19 mailing-listx_refsource_MLISTExploit
- http://secunia.com/advisories/35839 third-party-advisoryx_refsource_SECUNIAVendor Advisory
- http://www.openwall.com/lists/oss-security/2009/07/17/1 mailing-listx_refsource_MLIST
- http://www.vupen.com/english/advisories/2009/1925 vdb-entryx_refsource_VUPENPatchVendor Advisory
- https://access.redhat.com/security/cve/CVE-2009-1897 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=512284 x_refsource_CONFIRMIssue Tracking
- https://exchange.xforce.ibmcloud.com/vulnerabilities/51803 vdb-entryx_refsource_XF
- https://nvd.nist.gov/vuln/detail/CVE-2009-1897
- https://www.cve.org/CVERecord?id=CVE-2009-1897
- https://www.redhat.com/en/blog/security-flaws-caused-compiler-optimizations x_refsource_MISC
Change history (0)
No recorded changes yet.