Missing XPC Client & NSXPC endpoint validation leads to privilege escalation in Vienna Assistant (MacOS) - Vienna Symphonic Library
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: no
- Technical impact: total
Summary
The VSL privileged helper does utilize NSXPC for IPC. The implementation of the "shouldAcceptNewConnection" function, which is used by the NSXPC framework to validate if a client should be allowed to connect to the XPC listener, does not validate clients at all. This means that any process can connect to this service using the configured protocol. A malicious process is able to call all the functions defined in the corresponding HelperToolProtocol. No validation is performed in the functions "writeReceiptFile" and “runUninstaller” of the HelperToolProtocol. This allows an attacker to write files to any location with any data as well as execute any file with any arguments. Any process can call these functions because of the missing XPC client validation described before. The abuse of the missing endpoint validation leads to privilege escalation.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Vienna Symphonic Library GmbH Vienna Assistant
1.2.542