ZDI-26-555: Parallels RAS Client RDP Backend Service Exposed Dangerous Function Local Privilege Escalation Vulnerability
This vulnerability allows local attackers to escalate privileges on affected installations of Parallels RAS Client. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the RAS RDP Backend Service. The issue results from an exposed dangerous function. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM.
Other sources
This vulnerability allows local attackers to escalate privileges on affected installations of Parallels RAS Client. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2026-18262.
— ZDI
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Parallels RAS Client RDP Backend Serviceto a version that resolves this vulnerability.Patch ZDI-26-555 - Compensating control
Mitigate exposure of the RAS RDP Backend Service’s exposed dangerous function by restricting access to the service to only required/local management contexts, reducing the ability for low-privileged code to reach the vulnerable function.
Event History
Frequently Asked Questions
What is the severity of ZDI-26-555?
The severity of ZDI-26-555 is rated as 7.8 on the CVSS scale.
How do I fix ZDI-26-555?
To fix ZDI-26-555, ensure that you update to the latest version of Parallels RAS Client that addresses this vulnerability.
What type of vulnerability is ZDI-26-555?
ZDI-26-555 is a local privilege escalation vulnerability affecting Parallels RAS Client.
Who is affected by ZDI-26-555?
Individuals and organizations using affected installations of Parallels RAS Client are at risk from ZDI-26-555.
What is required to exploit ZDI-26-555?
An attacker must have the ability to execute low-privileged code on the target system to exploit ZDI-26-555.