exim: hard-link following vulnerability in mailbox handling
Published Jun 7, 2010
4.4
MEDIUMCVSS 2.0
EPSS 0.28%
Description
transports/appendfile.c in Exim before 4.72, when a world-writable sticky-bit mail directory is used, does not verify the st_nlink field of mailbox files, which allows local users to cause a denial of service or possibly gain privileges by creating a hard link to another user's file.
Affected products
No data.
- ≤ 4.71
- 4.10
- 4.20
- 4.21
- 4.22
- 4.23
- 4.24
- 4.30
- 4.31
- 4.32
- 4.33
- 4.34
- 4.40
- 4.41
- 4.42
- 4.43
- 4.44
- 4.50
- 4.51
- 4.52
- 4.53
- 4.54
- 4.60
- 4.61
- 4.62
- 4.63
- 4.64
- 4.65
- 4.66
- 4.67
- 4.68
- 4.69
- 4.70
No data.
Red Hat Enterprise Linux 4
exim
Affected
Red Hat Enterprise Linux 5
exim
Affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 4 | exim | Affected | n/a |
| Red Hat Enterprise Linux 5 | exim | Affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
The Red Hat Security Response Team has rated this issue as having low security impact. By default, /var/spool/mail/ is not provided with permissions to make an attack scenario possible, and there is no reason for permissions to be relaxed in such a way as to make it possible. We therefore have no plans to fix this flaw in Red Hat Enterprise Linux 4 or 5.
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:P/I:P/A:P
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 2, 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 2, 2026 | 0.28% (0.00280) | 18.54th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.28% (0.00280) | 19.49th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.09% (0.00089) | 23.27th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.04% (0.00044) | 11.89th | v3 (v2023.03.01) |
| Jul 2, 2024 | 0.04% (0.00044) | 10.25th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.04% (0.00044) | 8.24th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.55% (0.01547) | 74.98th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.55% (0.01547) | 74.94th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.55% (0.01547) | 72.92th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.55% (0.01547) | 51.82th | v2 (v2022.01.01) |
References (21)
- http://archives.neohapsis.com/archives/fulldisclosure/2010-06/0079.html mailing-listx_refsource_FULLDISC
- http://bugs.exim.org/show_bug.cgi?id=988 x_refsource_CONFIRM
- http://lists.exim.org/lurker/message/20100524.175925.9a69f755.en.html mailing-listx_refsource_MLIST
- http://lists.fedoraproject.org/pipermail/package-announce/2010-June/042587.html vendor-advisoryx_refsource_FEDORA
- http://lists.fedoraproject.org/pipermail/package-announce/2010-June/042613.html vendor-advisoryx_refsource_FEDORA
- http://lists.opensuse.org/opensuse-security-announce/2010-08/msg00001.html vendor-advisoryx_refsource_SUSE
- http://secunia.com/advisories/40019 third-party-advisoryx_refsource_SECUNIAVendor Advisory
- http://secunia.com/advisories/40123 third-party-advisoryx_refsource_SECUNIA
- http://secunia.com/advisories/43243 third-party-advisoryx_refsource_SECUNIA
- http://vcs.exim.org/viewvc/exim/exim-doc/doc-txt/ChangeLog?view=markup&pathrev=exim-4_72_RC2 x_refsource_CONFIRM
- http://vcs.exim.org/viewvc/exim/exim-src/src/transports/appendfile.c?r1=1.24&r2=1.25 x_refsource_CONFIRMPatch
- http://www.securityfocus.com/archive/1/511653/100/0/threaded mailing-listx_refsource_BUGTRAQ
- http://www.securityfocus.com/bid/40451 vdb-entryx_refsource_BID
- http://www.ubuntu.com/usn/USN-1060-1 vendor-advisoryx_refsource_UBUNTU
- http://www.vupen.com/english/advisories/2010/1402 vdb-entryx_refsource_VUPEN
- http://www.vupen.com/english/advisories/2011/0364 vdb-entryx_refsource_VUPEN
- https://access.redhat.com/security/cve/CVE-2010-2023 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=600093 x_refsource_CONFIRMIssue Tracking
- https://exchange.xforce.ibmcloud.com/vulnerabilities/59043 vdb-entryx_refsource_XF
- https://nvd.nist.gov/vuln/detail/CVE-2010-2023
- https://www.cve.org/CVERecord?id=CVE-2010-2023
Change history (0)
No recorded changes yet.