Rapid7 Vulnerability & Exploit Database

Cyrus IMAPD pop3d popsubfolders USER Buffer Overflow

Back to Search

Cyrus IMAPD pop3d popsubfolders USER Buffer Overflow



This exploit takes advantage of a stack based overflow. Once the stack corruption has occurred it is possible to overwrite a pointer which is later used for a memcpy. This gives us a write anything anywhere condition similar to a format string vulnerability. NOTE: The popsubfolders option is a non-default setting. I chose to overwrite the GOT with my shellcode and return to it. This defeats the VA random patch and possibly other stack protection features. Tested on gentoo-sources Linux 2.6.16. Although Fedora CORE 5 ships with a version containing the vulnerable code, it is not exploitable due to the use of the FORTIFY_SOURCE compiler enhancement


  • bannedit <bannedit@metasploit.com>
  • jduck <jduck@metasploit.com>




Module Options

To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':

msf > use exploit/linux/pop3/cyrus_pop3d_popsubfolders
msf exploit(cyrus_pop3d_popsubfolders) > show targets
msf exploit(cyrus_pop3d_popsubfolders) > set TARGET < target-id >
msf exploit(cyrus_pop3d_popsubfolders) > show options
    ...show and set options...
msf exploit(cyrus_pop3d_popsubfolders) > exploit

Time is precious, so I don’t want to do something manually that I can automate. Leveraging the Metasploit Framework when automating any task keeps us from having to re-create the wheel as we can use the existing libraries and focus our efforts where it matters.

– Jim O’Gorman | President, Offensive Security