Stunnel -n option in client mode contains format string

stunnel-client-format-string (7741) The risk level is classified as HighHigh Risk


Michael Trojnara's Stunnel is vulnerable to a format string attack when using the -n option with the smtp, pop, and nntp client modes. A malicious Web site operator can use this vulnerability to execute arbitrary code on the system with stunnel user privileges.


Gain Privileges


Upgrade to the latest version of stunnel (3.22 or later) available from the Stunnel web site. See References.

For EnGarde Secure Linux 1.0.1 (Finestra):
Upgrade to the latest version of stunnel (3.22-1.0.4 or later), as listed in EnGarde Secure Linux Security Advisory ESA-20011227-01. See References.

For Red Hat Linux 7.2:
Upgrade to the latest version of stunnel (3.22-1 or later), as listed in Red Hat Linux Errata Advisory RHSA-2002:002-10. See References.

For Mandrake Linux 8.1:
Upgrade to the latest version of stunnel (3.22-1.1mdk or later), as listed in MandrakeSoft Security Advisory MDKSA-2002:004 : stunnel. See References.

For other distributions:
Contact your vendor for upgrade or patch information.


Platforms Affected:

  • EngardeLinux Secure Community 1.0.1
  • MandrakeSoft Mandrake Linux 8.1
  • MandrakeSoft Mandrake Linux 8.1 IA64
  • RedHat Linux 7
  • RedHat Linux 7.1
  • RedHat Linux 7.2
  • RedHat Linux 7.3
  • stunnel stunnel


Dec 22, 2001

The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (IBM Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

For corrections or additions please email ignore thisxforceignore this@ignore thisus.ignore thisibm.comignore this

Return to the main page