\ CVE-2018-6854 - Buffer Errors vulnerability in Sophos products | Vumetric Cyber Portal

CVE-2018-6854 - Buffer Errors vulnerability in Sophos products

Publication

2018-07-09

Last modification

2019-10-03

Summary

Sophos SafeGuard Enterprise before 8.00.5, SafeGuard Easy before 7.00.3, and SafeGuard LAN Crypt before 3.95.2 are vulnerable to Local Privilege Escalation via multiple IOCTLs, e.g., 0x8810200B, 0x8810200F, 0x8810201B, 0x8810201F, 0x8810202B, 0x8810202F, 0x8810203F, 0x8810204B, 0x88102003, 0x88102007, 0x88102013, 0x88102017, 0x88102027, 0x88102033, 0x88102037, 0x88102043, and 0x88102047. When some conditions in the user-controlled input buffer are not met, the driver writes an error code (0x2000001A) to a user-controlled address. Also, note that all the aforementioned IOCTLs use transfer type METHOD_NEITHER, which means that the I/O manager does not validate any of the supplied pointers and buffer sizes. So, even though the driver checks for input/output buffer sizes, it doesn't validate if the pointers to those buffers are actually valid. So, we can supply a pointer for the output buffer to a kernel address space address, and the error code will be written there. We can take advantage of this condition to modify the SEP_TOKEN_PRIVILEGES structure of the Token object belonging to the exploit process and grant SE_DEBUG_NAME privilege. This allows the exploit process to interact with higher privileged processes running as SYSTEM and execute code in their security context.

Classification

CWE-119 - Buffer Errors

Risk level (CVSS AV:L/AC:L/Au:N/C:C/I:C/A:C)

High

7.2

Access Vector

  • Network
  • Adjacent Network
  • Local

Access Complexity

  • Low
  • Medium
  • High

Authentication

  • None
  • Single
  • Multiple

Confident. Impact

  • Complete
  • Partial
  • None

Integrity Impact

  • Complete
  • Partial
  • None