Blat 3.2.14 - Stack Overflow

1.       Vulnerable Product Version:

*Blat v3.2.14*
Link: blat.net


2.       Vulnerability Information

Impact: Attacker may gain administrative access / can perform a DOS

Remotely Exploitable: No

Locally Exploitable: May be possible


3.       Product Details

An open source Windows (32 & 64 bit) command line SMTP mailer. We can use
it to automatically email logs, the contents of a html FORM, or whatever
else you need to send.

Since blat is lightweight, user friendly and simple (but awesome) many
vendors incorporates it with their Softwares. I have seen blat in many
commercial Softwares which use it for sending mails to its customers. And
Blat is awesome.


4.       Vulnerability Description

The Overflow vulnerability lies in the profile option parameter “–p”. When
a string of 236 bytes is send to blat, the EBP and EIP register gets
overwritten by the user input.

Reproduction:

*                blat.exe crashes with this command blat.exe –install
smtp.my.tld 127.0.0.1 –p <”A”*234+”B”*2>*


Feeding this command overwrites EBP with 0x00410041 and EIP with 0x00420042
(Please refer to the attached screen shot)


5.       Links

https://sourceforge.net/projects/blat/

https://groups.yahoo.com/neo/groups/blat/conversations/messages/13759