Public Date:
600093: CVE-2010-2023 exim: hard-link following vulnerability in mailbox handling

The MITRE CVE dictionary describes this issue as:

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.

Find out more about CVE-2010-2023 from the MITRE CVE dictionary dictionary and NIST NVD.


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.

CVSS v2 metrics

NOTE: The following CVSS v2 metrics and score provided are preliminary and subject to review.

Base Score 4.3
Base Metrics AV:N/AC:M/Au:N/C:N/I:P/A:N
Access Vector Network
Access Complexity Medium
Authentication None
Confidentiality Impact None
Integrity Impact Partial
Availability Impact None

Find out more about Red Hat support for the Common Vulnerability Scoring System (CVSS).

Affected Packages State

Platform Package State
Red Hat Enterprise Linux 4 exim Affected
Red Hat Enterprise Linux 5 exim Affected