BusyBox up to 1.23.1/1.4.x cmdline arp_main IFNAME memory corruption

Summaryinfo

A vulnerability classified as critical was found in BusyBox up to 1.23.1/1.4.x. Affected is the function arp_main of the component cmdline. Such manipulation of the argument IFNAME leads to memory corruption. The attack must be carried out locally. There is no available exploit. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability, which was classified as critical, has been found in BusyBox up to 1.23.1/1.4.x. Affected by this issue is the function arp_main of the component cmdline. The manipulation of the argument IFNAME with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability.

The weakness was presented 01/01/2017 by 0x721427D8 as SSD Advisory – BusyBox (local) cmdline stack buffer overwrite as confirmed advisory (Blog). The advisory is shared for download at blogs.securiteam.com. The public release was coordinated in cooperation with the vendor. The attack needs to be approached locally. The successful exploitation requires a simple authentication. There are known technical details, but no exploit is available. The following code is the reason for this vulnerability:

if (opts & (ARP_OPT_d | ARP_OPT_s)) {
   if (argv[0] == NULL)
      bb_error_msg_and_die("need host name");
   if (opts & ARP_OPT_s)
      return arp_set(argv);
   return arp_del(argv);
}

By providing an overly long string for param IFNAME while setting -D (read HW Address from IFACE) and -s (set new entry) a strcpy operation can be reached that allows to write past the stack buffer ifreq.ifr_name[IFANMESIZ] [5,6]

Applying a patch is able to eliminate this problem. The bugfix is ready for download at bugs.busybox.net. The advisory contains the following remark:

strcpy => strncpy(dst,src,n=sizeof(ifreq.ifr_name)-1) or less error prone but more overhead snprintf()

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Affected

• BusyBox 1.3.x

Productinfo

Name

• BusyBox

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.23.0
• 1.23.1

License

• open-source

CPE 2.3info

• 🔍
• 🔍
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CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

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CVSSv2info

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Threat Intelligenceinfo

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Entryinfo

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