[UNIX] cftp Local Buffer Overflow Vulnerability

The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
- - promotion

The SecuriTeam alerts list - Free, Accurate, Independent.

Get your security news from a reliable source.
http://www.securiteam.com/mailinglist.html

- - - - - - - - -



cftp Local Buffer Overflow Vulnerability
------------------------------------------------------------------------


SUMMARY

<http://ftp.giga.or.at/pub/nih/cftp/> CFTP is "Comfortable FTP, a full
screen ftp client. Supported are FTP both with active and passive data
connections, IPv4 and IPv6, and SFTP (a file transfer protocol using SSH
for authorization and connection encryption)". cftp has been found to
contain a local buffer overflow in readrc() with sprintf() with no sizelen
control.

DETAILS

Vulnerable Systems:
* cftp version 0.12

Source error:
int readrc(char **userp, char **passp, char **hostp, char **portp, char
**wdirp, int check_alias)
{
FILE *f;
char b[8192], *p, *tok, *q, *home;
char *user, *pass, *host, *port, *wdir;

if ((home=getenv("HOME")) == NULL)
home = "";
sprintf(b, "%s/.cftprc", home);

if ((f=fopen(b, "r")) == NULL) {
if (errno == ENOENT)
return 0;
return -1;
}
[..]
}

error in sprintf(), no sizelen control in getenv().

Proof of concept:
$ export HOME=`perl -e "print 'A'x8200"`
$ cftp
Segmentation fault
$


ADDITIONAL INFORMATION

The information has been provided by <mailto:starcadi@xxxxxxxxx>
starcadi.



========================================


This bulletin is sent to members of the SecuriTeam mailing list.
To unsubscribe from the list, send mail with an empty subject line and body to: list-unsubscribe@xxxxxxxxxxxxxx
In order to subscribe to the mailing list, simply forward this email to: list-subscribe@xxxxxxxxxxxxxx


====================
====================

DISCLAIMER:
The information in this bulletin is provided "AS IS" without warranty of any kind.
In no event shall we be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages.

Relevant Pages