Final Event Style Sample Challenge - KPRCA_00058

Original Versions

Known Vulnerabilities

  • CWE-121 - Stack-based Buffer Overflow
  • CWE-190 - Integer Overflow or Wraparound

DARPA performer group

Kaprica Security (KPRCA)


A secure authentication service with an extensible protocol that can support multiple authentication methods and multiple upper layer services.

Feature List

Full support for the cleartext password authentication method; user can change password using a change request.

Timing attack resistance to prevent exposure of usernames and passwords.

Packets are padded to 8-byte boundaries with random data to make it easier to implement on top of a secure channel in the future.


Vuln 1

In service.c:285, there is an integer overflow that allows an attacker to bypass the length check. This vulnerable function is called from service.c:513 and is passed a stack buffer of a fixed size. An attacker is able to use the integer overflow to cause the stack buffer to overflow if they give a string length of 0xFFFFFFFF and a packet with 0x8000 bytes of data. This is provable with a type 1 POV.

Generic class of vulnerability

Buffer overflow

CWE classification

CWE-121: Stack-based Buffer Overflow

CWE-190: Integer Overflow or Wraparound


No major challenges. Requires reasoning about integer overflows and function argument types.


  • Discovery: easy
  • Proving: easy
  • Fixing: medium

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