cbcvebase.
CVE-2006-0058
published 2006-03-22

CVE-2006-0058: Signal 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 causes…

PriorityP356high7.6CVSS 2.0
AVNACHAuNCCICAC
EXPLOIT
EPSS
28.14%
97.9th percentile
Signal 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 causes the setjmp and longjmp function calls to be interrupted and modify unexpected memory locations.

Affected

11 ranges
VendorProductVersion rangeFixed in
debiansendmail< sendmail 8.13.6-1 (bookworm)sendmail 8.13.6-1 (bookworm)
sendmailsendmail
sendmailsendmail
sendmailsendmail
sendmailsendmail
sendmailsendmail
sendmailsendmail
sendmailsendmail>= 0 < 8.13.6-18.13.6-1
sendmailsendmail>= 0 < 8.13.6-18.13.6-1
sendmailsendmail>= 0 < 8.13.6-18.13.6-1
sendmailsendmail>= 0 < 8.13.6-18.13.6-1

Detection & IOCsextracted from sources · hover to see the quote

urlftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-06:13/sendmail410.patch
urlftp://ftp.sendmail.org/pub/sendmail/8.13.5.p0
hash9442f310b50ab21962feb69004324752a705e598
hashccd79b18310db610cfeeff97a3a807347888250f
  • The exploit targets Sendmail 8.13.x before 8.13.6 on TCP port 25. Detection should look for SMTP sessions that send an unusually large DATA payload (~32764 bytes of 0x7f bytes) followed by repeated probe sequences to trigger a signal handler race condition.
  • The exploit sends a payload buffer filled with 0x7f bytes (32764 bytes) as the message body to trigger the timeout race. Network signatures should look for SMTP DATA bodies consisting predominantly of 0x7f bytes at this size.
  • The attack exploits the race between setjmp/longjmp and asynchronous signal handling in Sendmail. The attacker forces an I/O timeout at a precise moment during SMTP DATA phase. Monitor for SMTP 451 timeout responses immediately following a large DATA submission as a potential exploitation indicator.
  • The vulnerability also involves a buffer in sm_syslog() that could be used as an attack vector. Monitor sendmail log entries for anomalous or oversized syslog messages that may indicate exploitation attempts.
  • ·On Red Hat Enterprise Linux 2.1, Sendmail is configured by default to only accept connections from localhost, limiting remote exploitability to instances where Sendmail has been reconfigured to listen on external interfaces.
  • ·There is no known workaround for this vulnerability other than completely disabling sendmail.
  • ·The CERT-supplied patch may generate compiler warnings about offsets, which CERT and Sendmail consider harmless. Additionally, on systems where time_t != int (e.g., s390x), the original patch caused a regression and required modification.

CVSS provenance

nvdv2.07.6HIGHAV:N/AC:H/Au:N/C:C/I:C/A:C
osv7.6HIGH
vendor_debian7.6HIGH
vendor_redhat7.6HIGH
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