[Full-disclosure] [UPH-07-02] Firefly Media Server DoS

[nnp]

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[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


- --
http://www.smashthestack.org
http://www.unprotectedhex.com
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