Streamripper 1.62.1 Security Advisory | http://streamripper.sf.net
Multiple Buffer Overflows
12 August 2007

Chris Rohlf
http://em386.blogspot.com

-----------
Description
-----------

Streamripper is a program used to rip streaming media to mp3 format to
your harddrive. 

Multiple buffer overflows that allow for arbitrary code execution have
been found in the HTTP header parsing code.

Other projects based on the same code may also be affected including 
the Windows winamp streamripper plugin (this is unconfirmed)

-------
Details
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There are multiple buffer overflows in the HTTP header parsing code that 
would allow a malicious server to execute code on the machine of any streamripper 
client that connects to it. The problem specifically exists in lib/http.c 
in function httplib_parse_sc_header() on line 324

The function extract_header_value() is called with the string 'Location:'

lib/http.c
...
extract_header_value(header, info->http_location, "Location:");
...
        int extract_header_value (char *header, char *dest, char *match)
        {
            char* start = (char *)strstr(header, match);
            if (start) {
                subnstr_until(start+strlen(match), "\n", dest, MAX_ICY_STRING);
                return 1;
            } else {
                return 0;
            }
        }
...
lib/mchar.c
...
        char *subnstr_until(const char *str, char *until, char *newstr, int maxlen)
        {
            const char *p = str;
            int len = 0;

            for(len = 0; strncmp(p, until, strlen(until)) != 0 && len < maxlen; p++)
            {
                newstr[len] = *p;
                len++;
            }
            newstr[len] = '\0';

            return newstr;
        }
...

extract_header_value() makes the assumption that info->http_location is 
MAX_ICY_STRING (4024) bytes in size. However info->http_location is only
MAX_HOST_LEN (512) bytes. 

The same assumption is made for the HTTP header string 'Server:' which is only
MAX_SERVER_LEN (1024) bytes in length.

Both overflows can be leveraged to execute arbitrary code.

New versions have been uploaded to sourceforge.net