RE: *ALERT* BID 3581: Wu-Ftpd File Globbing Heap Corruption Vulnerability

From: Craig Leikis (cleikisat_private)
Date: Thu Nov 29 2001 - 12:29:00 PST

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    On Solaris 8, running wu-ftpd 2.6.1(1) ls "~{" didn't cause a problem, but
    "dir ~{" did. It produced the following log message:
    
    Nov 29 13:50:07 xxx ftpd[6132]: [ID 148269 daemon.error] exiting on signal
    11
    
    On Thu, 29 Nov 2001, Junius, Martin wrote:
    
    > > I am running the a linux port of the bsd ftpd and it might be
    > > vulnerable to
    > > a similar attack,
    > >
    > > ftp localhost
    > > Connected to localhost.
    > > 220 playlandFTP server (Version 6.5/OpenBSD, linux port 0.3.3) ready.
    > > Name (localhost:user): ftp
    > > 331 Guest login ok, type your name as password.
    > > Password:
    > > 230 Guest login ok, access restrictions apply.
    > > Remote system type is UNIX.
    > > Using binary mode to transfer files.
    > > ftp> ls ~{
    > > 200 PORT command successful.
    > > 421 Service not available, remote server has closed connection
    > >
    > > in inetd I find an error stating that the ftpd process has
    > > died unexpectedly
    > >
    > > Nov 28 14:21:28 playland inetd[82]: pid 16341: exit signal 11
    >
    > I just did some tests with RedHat 7.2, glibc-2.2.4-19, and ftpd-BSD-0.3.2.
    > "ls ~{" makes the ftpd process die in glibc´s glob(pattern="~{", ...)
    > function with a SEGV. Beside that ftpd-BSD uses globfree() to release
    > the memory. So as long as glibc's glob() is safe, ftpd-BSD *should*
    > be safe against this exploit.
    >
    > On RedHat 6.2, glibc-2.1.3-22, "ls ~{" simply returns "No such file
    > or directory".
    >
    > Martin
    >
    



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