Topic : IPFilter (ippool) 4.1.31 lib/load_http.c buffer overflow
SecurityAlert : 62
CVE : CVE-2009-1476
SecurityRisk : Low (About)
Remote Exploit : No
Local Exploit : Yes
Exploit Given : No
Credit : Maksymilian Arciemowicz
Date : 22.05.2009
Affected Software : | IPFilter (ippool) 4.1.31 |
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Hash: SHA1
[ IPFilter (ippool) 4.1.31 lib/load_http.c buffer overflow ]
Author: Maksymilian Arciemowicz
http://SecurityReason.com/
Date:
- - Dis.: 05.03.2009
- - Pub.: 22.05.2009
CVE: CVE-2009-1476
Risk: Low
Original URL:
http://securityreason.com/achievement_securityalert/62
- --- 0.Description ---
IPFilter is a software package that can be used to provide network address
translation (NAT) or firewall services. To use, it can either be used as a
loadable kernel module or incorporated into your UNIX kernel; use as a
loadable kernel module where possible is highly recommended. Scripts are
provided to install and patch system files, as required.
ippool - user interface to the IPFilter pools
Ippool is used to manage information stored in the IP pools subsystem of
IPFilter. Configuration file information may be parsed and loaded into the
kernel, currently configured pools removed or changed as well as
inspected.
- --- 1. IPFilter (ippool) 4.1.31 lib/load_http.c buffer overflow ---
The main problem exist in lib/load_http.c .
Let's see lib/load_http.c ( char buffer[1024] )
- ---
...
alist_t *
load_http(char *url)
{
int fd, len, left, port, endhdr, removed;
char *s, *t, *u, buffer[1024], *myurl;
alist_t *a, *rtop, *rbot;
struct sockaddr_in sin;
struct hostent *host;
/*
* More than this would just be absurd.
*/
if (strlen(url) > 512) {
fprintf(stderr, "load_http has a URL > 512 bytes?!\n");
return NULL;
}
fd = -1;
rtop = NULL;
rbot = NULL;
sprintf(buffer, "GET %s HTTP/1.0\r\n", url);
myurl = strdup(url);
if (myurl == NULL)
goto done;
s = myurl + 7; /* http:// */
t = strchr(s, '/');
if (t == NULL) {
fprintf(stderr, "load_http has a malformed URL '%s'\n", url);
free(myurl);
return NULL;
}
*t++ = '\0';
u = strchr(s, '@');
if (u != NULL)
s = u + 1; /* AUTH */
sprintf(buffer + strlen(buffer), "Host: %s\r\n\r\n", s);
...
- ---
0. buffer[] have only 1024 bytes,
1. url can't have more than 512 bytes,
2. url will be copied into buffer here:
sprintf(buffer, "GET %s HTTP/1.0\r\n", url);
and here (s is a host)
sprintf(buffer + strlen(buffer), "Host: %s\r\n\r\n", s);
so if the url have
512 = strlen(http:// A x504 /)
then into buffer will be put
strlen(GET HTTP/1.0\r\n) = 15
strlen(url) = 512
strlen(Host: \r\n\r\n)= 10
strlen(A x504) = 504
sum = 1041 bytes.
Any use of this function is a potential risk. Programs such as "ippool" may
be at risk.
- --- 2. Fix ---
NetBSD fix:
http://cvsweb.netbsd.org/bsdweb.cgi/src/dist/ipf/lib/load_http.c?only_with_
tag=MAIN
- --- 3. Greets ---
Christos Zoulas
sp3x infospec chujwamwdupe pi3 and others
- --- 4. Contact ---
Author: SecurityReason.com [ Maksymilian Arciemowicz ]
Email: cxib [a.t] securityreason [d00t] com
GPG: http://securityreason.com/key/Arciemowicz.Maksymilian.gpg
http://securityreason.com
http://securityreason.pl
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