OpenTelemetry.Resources.Host vulnerable to arbitrary code execution via local PATH hijacking on macOS

Summary

The OpenTelemetry.Resources.Host NuGet package is affected by an untrusted search path vulnerability on macOS. The host.id resource attribute detector launches the sh and ioreg executables by bare name rather than by absolute path, so both are resolved
through the PATH environment variable.

A local attacker who is less privileged than the host application, and who can influence PATH or write to a directory that appears in PATH ahead of the system directories, can have an arbitrary binary executed in the application's security context, resulting in local
code execution/privilege escalation.

Details

The implementation of the host detector macOS has always invoked ioreg and sh via their bare names since it was implemented by open-telemetry/opentelemetry-dotnet-contrib#1631.

The vulnerability was fixed by open-telemetry/opentelemetry-dotnet-contrib#4760 which executes ioreg directly using its absolute path.

Impact

Applications running on macOS that use the OpenTelemetry.Resources.Host detector when an attacker who is less privileged than the application process can influence PATH or write to a PATH directory that precedes the system directories (e.g. a higher-privileged service with a user-writable directory in its search path, or a process inheriting an attacker-influenced environment). The attacker gains code execution in the application's security context through an attacker-controlled ioreg executable.

Mitigation

This vulnerability only affect macOS hosts - Linux and Windows hosts are unaffected.

Workarounds

None known.

References

• GHSA-9h8m-3fm2-qjrq
• open-telemetry/opentelemetry-dotnet-contrib#4760
• CWE-426