What’s Vulnerable › Vulnerabilities

CVE-2006-4434

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2006-08-29 · updated 2026-06-16
• Weakness: CWE-416

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."

Affected products

• Sendmail: before 8.13.8 — fixed in 8.13.8

How to fix

Upgrade to a fixed version: Sendmail 8.13.8. Check the vendor advisory for mitigations.

References

• http://secunia.com/advisories/21637
• http://secunia.com/advisories/21641
• http://secunia.com/advisories/21696
• http://secunia.com/advisories/21700
• http://secunia.com/advisories/21749
• http://secunia.com/advisories/22369
• http://securitytracker.com/id?1016753
• http://sunsolve.sun.com/search/document.do?assetkey=1-26-102664-1
• http://www.attrition.org/pipermail/vim/2006-August/000999.html
• http://www.debian.org/security/2006/dsa-1164
• http://www.mandriva.com/security/advisories?name=MDKSA-2006:156
• http://www.novell.com/linux/security/advisories/2006_21_sr.html

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