[UPH-07-02]
UnprotectedHex.com security advisory [07-02]
Discovered by nnp

Discovered : 1 August 2007
Reported to the vendor : 13 October 2007
Fixed by vendor : 21 October 2007

Vulnerability class : Remote DoS

Affected product : mt-dappd/Firefly Media Server
Version : <= 0.2.4
Product details: 
www.fireflymediaserver.org/ 
'''
The purpose of this project is built the best server software to serve digital music to the Roku Soundbridge and iTunes; to be able to serve the widest variety of digital music content over the widest range of devices
'''

File/Function/line : webserver.c/ws_decodepassword/1399

Cause: Null pointer dereference. There is an unchecked increment of the 'header' variable until a space character is encountered. If a space character is not encountered the pointer is incremented/dereferenced until out of bounds memory is hit. Exploiting this depends on the state of memory at the time so the exploit constantly sends a header with no data as part of the authorization header until a crash occurs. This typically occurs within seconds.

    /* xlat table is initialized */
    while(*header != ' ')
    header++;

Proof of concept code : Yes