CVE Vulnerabilities

CVE-2006-4434

Use After Free

Published: Aug 29, 2006 | Modified: Apr 03, 2025
CVSS 3.x
7.5
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

Use-after-free vulnerability in Sendmail before 8.13.8 allows remote attackers to cause a denial of service (crash) via a long header line, which causes a previously freed variable to be referenced. NOTE: the original developer has disputed the severity of this issue, saying The only denial of service that is possible here is to fill up the disk with core dumps if the OS actually generates different core dumps (which is unlikely)… the bug is in the shutdown code (finis()) which leads directly to exit(3), i.e., the process would terminate anyway, no mail delivery or receiption is affected.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Name Vendor Start Version End Version
Sendmail Sendmail * 8.13.8 (excluding)
Sendmail Ubuntu dapper *
Sendmail Ubuntu devel *
Sendmail Ubuntu edgy *
Sendmail Ubuntu feisty *
Sendmail Ubuntu gutsy *
Sendmail Ubuntu hardy *
Sendmail Ubuntu intrepid *
Sendmail Ubuntu jaunty *
Sendmail Ubuntu karmic *
Sendmail Ubuntu upstream *

Potential Mitigations

References