Executive brief
The Palo Alto Networks Terminal Services Agent, which identifies users on multi-user Windows systems for security policy enforcement, contains a flaw that allows a local user to gain administrative control. By running a malicious program on a system where the agent is installed, an attacker can bypass security restrictions and take full control of the machine. This could lead to unauthorized access to sensitive data or the disruption of corporate network security policies.
Technical details
A local privilege escalation vulnerability exists in the Palo Alto Networks Terminal Services Agent (specifically the panta.sys driver) due to an integer overflow. When processing a specific IOCTL (0x88002200), the driver performs a multiplication on a user-supplied size value that can wrap around, leading to a small pool allocation. A subsequent loop uses the original, large size value to perform a memset or write operation, resulting in an out-of-bounds write (CWE-787) into kernel memory. An attacker with local access can exploit this to execute arbitrary code with kernel-level privileges. The issue is resolved in Terminal Services Agent version 7.0.7.
Affected products
- Palo Alto Networks Terminal Services Agent 6.0, 7.0.0 through 7.0.6
Timeline
- 2017-01-26: advisory: Palo Alto Networks published security advisory PAN-SA-2017-0001
- 2017-01-26: disclosed: Exploit code published on Exploit-DB by Parvez Anwar
- 2017-01-27: patched: NVD publication date; fix available in version 7.0.7