Re: [Full-disclosure] [+] Vulnerability in less version 394 and prior

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glopeda.com wrote:
From: glopeda@xxxxxxxxxxx
Application: less 394 and prior
Type: Format strings vulnerability
Priority: Low

There exists a format strings bug in the less application present in
most flavors of UNIX. It could be leveraged for privilege escalation
if the calling application is setuid/setgid and does not properly drop
privileges.

Meager demonstration:
$ export LESSOPEN=%s%n
$ less somefile
Segmentation fault
$

See http://www.glopeda.com for more details.


Still some strangeness on the latest version:
smithj@localhost ~ $ export LESSOPEN=%s%n
smithj@localhost ~ $ less route.txt
*** %n in writable segment detected ***
Aborted
smithj@localhost ~ $ conary query less
less=409-1-0.1[is: x86]

Given the details in the original post, I don't think this is a security
issue. If a program doesn't properly shed s{u,g}id bits, that program
should be fixed. This is still a bug, though, so I'm CCing the
maintainer on this email.

smithj


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