CVE-2006-4434: sendmail Use After Free

Vulnerability summary

CVE-2006-4434 is a high (CVSS 7.5) Use After Free vulnerability in sendmail. EPSS estimates a 4.55% chance of exploitation in the next 30 days, higher than 91.4% of scored vulnerabilities.

Timeline

1. 29-08-2006
   PublishedVulnerability first disclosed.
2. 07-08-2024
   Last modifiedVulnerability information updated.

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."

• CWE-416Use After FreeThe 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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.