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Vulnerability record · CVE-2006-4434 · published 29 August 2006

CVE-2006-4434: Sendmail use after free vulnerability

Sendmail · Sendmail

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."

7.5 CVSS 3.1 High EPSS 4.5% · top 8.7% CWE-416 · Use after free
7.5CVSS 3.1 base score, v2 5.0
4.5%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
38References
16 Jun 2026Last modified by NVD

Description

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."

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://secunia.com/advisories/21637 Broken LinkPatchVendor Advisory
http://secunia.com/advisories/21641 Broken LinkPatchVendor Advisory
http://secunia.com/advisories/21696 Broken LinkVendor Advisory
http://secunia.com/advisories/21700 Broken LinkVendor Advisory
http://secunia.com/advisories/21749 Broken LinkVendor Advisory
http://secunia.com/advisories/22369 Broken LinkVendor Advisory
http://securitytracker.com/id?1016753 Broken LinkPatchThird Party AdvisoryVDB Entry
http://sunsolve.sun.com/search/document.do?assetkey=1-26-102664-1 Broken Link
http://www.attrition.org/pipermail/vim/2006-August/000999.html Mailing List
http://www.debian.org/security/2006/dsa-1164 Broken Link
http://www.mandriva.com/security/advisories?name=MDKSA-2006:156 Broken Link
http://www.novell.com/linux/security/advisories/2006_21_sr.html Broken Link
http://www.openbsd.org/errata.html#sendmail3 Release Notes
http://www.openbsd.org/errata38.html#sendmail3 Third Party Advisory
http://www.osvdb.org/28193 Broken Link
http://www.securityfocus.com/bid/19714 Broken LinkPatchThird Party AdvisoryVDB Entry
http://www.sendmail.org/releases/8.13.8.html Release Notes
http://www.vupen.com/english/advisories/2006/3393 Broken LinkVendor Advisory
http://www.vupen.com/english/advisories/2006/3994 Broken LinkVendor Advisory
http://secunia.com/advisories/21637 Broken LinkPatchVendor Advisory
http://secunia.com/advisories/21641 Broken LinkPatchVendor Advisory
http://secunia.com/advisories/21696 Broken LinkVendor Advisory
http://secunia.com/advisories/21700 Broken LinkVendor Advisory
http://secunia.com/advisories/21749 Broken LinkVendor Advisory
http://secunia.com/advisories/22369 Broken LinkVendor Advisory
http://securitytracker.com/id?1016753 Broken LinkPatchThird Party AdvisoryVDB Entry
http://sunsolve.sun.com/search/document.do?assetkey=1-26-102664-1 Broken Link
http://www.attrition.org/pipermail/vim/2006-August/000999.html Mailing List
http://www.debian.org/security/2006/dsa-1164 Broken Link
http://www.mandriva.com/security/advisories?name=MDKSA-2006:156 Broken Link
http://www.novell.com/linux/security/advisories/2006_21_sr.html Broken Link
http://www.openbsd.org/errata.html#sendmail3 Release Notes
http://www.openbsd.org/errata38.html#sendmail3 Third Party Advisory
http://www.osvdb.org/28193 Broken Link
http://www.securityfocus.com/bid/19714 Broken LinkPatchThird Party AdvisoryVDB Entry
http://www.sendmail.org/releases/8.13.8.html Release Notes
http://www.vupen.com/english/advisories/2006/3393 Broken LinkVendor Advisory
http://www.vupen.com/english/advisories/2006/3994 Broken LinkVendor Advisory

Track CVE-2006-4434 inside VULONE

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2003-0694Sendmail prescan buffer overflow allows remote code executionThe prescan function in Sendmail 8.12.9 contains a buffer overflow reachable through crafted email addresses, as demonstrated via the parseaddr funct…EPSS 66%analysed10.0CVE-2003-0161Sendmail vulnerabilityThe prescan() function in the address parser (parseaddr.c) in Sendmail before 8.12.9 does not properly handle certain conversions from char and int t…EPSS 39%10.0CVE-2002-1337Sendmail crackaddr buffer overflow allows remote code executionSendmail versions 5.79 through 8.12.7 contain a buffer overflow in the crackaddr function in headers.c, triggered by specially formatted sender and r…EPSS 73%analysed7.8CVE-2007-2246Sendmail vulnerabilityUnspecified vulnerability in HP-UX B.11.00 and B.11.11, when running sendmail 8.9.3 or 8.11.1; and HP-UX B.11.23 when running sendmail 8.11.1; allows…EPSS 2.3%7.6CVE-2006-0058Sendmail vulnerabilitySignal handler race condition in Sendmail 8.13.x before 8.13.6 allows remote attackers to execute arbitrary code by triggering timeouts in a way that…EPSS 29%7.5CVE-2009-4565Sendmail vulnerabilitysendmail before 8.14.4 does not properly handle a '\0' character in a Common Name (CN) field of an X.509 certificate, which (1) allows man-in-the-mid…EPSS 2.4%7.5CVE-2006-7175Sendmail vulnerabilityThe version of Sendmail 8.13.1-2 on Red Hat Enterprise Linux 4 Update 4 and earlier does not allow the administrator to disable SSLv2 encryption, whi…EPSS 0.82%7.5CVE-2003-0681Sendmail advanced message server vulnerabilityA "potential buffer overflow in ruleset parsing" for Sendmail 8.12.9, when using the nonstandard rulesets (1) recipient (2), final, or (3) mailer-spe…EPSS 22%

Source: NIST National Vulnerability Database (record CVE-2006-4434), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.