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How CVE-2026-62199 Works
OpenClaw is an open-source, cross-platform personal AI assistant distributed as the npm package openclaw. During the host execution phase, it applies a `host-env-security` policy to filter environment variable overrides passed by callers. The vulnerable function, sanitizeHostExecEnv, relies on `isDangerousHostEnvOverrideVarName` to determine which environment variables are blocked.
The filtering logic uses two primary mechanisms: a static blocklist (HOST_DANGEROUS_OVERRIDE_ENV_KEYS) and a set of dangerous prefixes (HOST_DANGEROUS_OVERRIDE_ENV_PREFIXES). However, this approach is incomplete. It fails to recognize pattern-based keys such as `CARGO_TARGET_CARGO_TARGET_<TARGET>_RUNNER, which follow a `CARGO_TARGET_` prefix with a suffix. Additionally, it does not block variables like RUSTC, RUSTDOC, RUSTC_WORKSPACE_WRAPPER, CARGO_BUILD_RUSTDOC, CARGO_BUILD_RUSTC_WORKSPACE_WRAPPER, MAKE, HGEDITOR, and `HGMERGE` – all of which are invoked directly by interpreters and build tools at startup.
When the affected environment-filtering feature is enabled and reachable, a lower-trust caller or a configured input path can supply crafted environment variables. By setting variables such as RUSTC, RUSTDOC, or `CARGO_TARGET__LINKER` to point to arbitrary executables, an attacker can hijack the host process during cargo, rustc, rustdoc, make, or `hg` invocations. This allows the execution or persistence of actions that extend far beyond the caller’s intended authorization.
The root cause is inadequate input sanitization within the host execution environment. The flaw operates at the system integration level, where trusted execution contexts do not adequately validate untrusted input sources. This is a classic case of environment variable injection and privilege escalation, classified under CWE-78 (OS Command Injection) and CWE-20 (Improper Input Validation). The vulnerability affects all OpenClaw versions before `2026.6.6` and is particularly dangerous when OpenClaw runs as a service or daemon with elevated permissions.
Attackers can leverage this flaw to execute arbitrary code with elevated privileges, establish persistence mechanisms, or gain unauthorized access to sensitive system resources. The threat aligns with MITRE ATT&CK techniques T1059.001 (Command and Scripting Interpreter) and T1548.002 (Abuse Elevation Control Mechanism). The persistence aspect is especially concerning when the vulnerable system maintains long-running processes that retain manipulated environment settings across multiple execution contexts.
DailyCVE Form:
Platform: ……. OpenClaw
Version: …….. < 2026.6.6
Vulnerability :…… Environment Variable Injection
Severity: ……. High (CVSS 8.8)
date: ………. 2026-07-13
Prediction: …… 2026-07-14
What Undercode Say:
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The vulnerability stems from an incomplete blocklist in the `isDangerousHostEnvOverrideVarName` function. The following code snippet from the vulnerable `src/infra/host-env-security.ts` illustrates the flawed logic:
// Vulnerable implementation (pre-2026.6.6)
function isDangerousHostEnvOverrideVarName(key: string): boolean {
const dangerousKeys = new Set([
'PATH', 'LD_LIBRARY_PATH', 'PYTHONPATH', 'NODE_OPTIONS'
// Missing: CARGO_TARGET__LINKER, RUSTC, MAKE, etc.
]);
const dangerousPrefixes = ['LD_', 'DYLD_'];
// No regex for CARGO_TARGET_<TARGET>_(LINKER|RUNNER)
return dangerousKeys.has(key) || dangerousPrefixes.some(p => key.startsWith(p));
}
The fix in version `2026.6.6` introduces a comprehensive regex and expands the blocklist:
// Fixed implementation (2026.6.6+)
const CARGO_TARGET_EXECUTABLE_OVERRIDE_ENV_KEY =
/^CARGO_TARGET_[A-Z0-9_]+_(?:LINKER|RUNNER)$/;
function isDangerousHostEnvOverrideVarName(key: string): boolean {
// Existing checks...
// New regex match
if (CARGO_TARGET_EXECUTABLE_OVERRIDE_ENV_KEY.test(key)) {
return true;
}
// Additional blocked keys
const blockedEverywhereKeys = new Set([
'CARGO_BUILD_RUSTC_WORKSPACE_WRAPPER',
'CARGO_BUILD_RUSTDOC',
'RUSTC',
'RUSTC_WORKSPACE_WRAPPER',
'RUSTDOC',
'MAKE',
'HGEDITOR',
'HGMERGE'
]);
return / ... / || blockedEverywhereKeys.has(key);
}
Exploit
An attacker with low-trust caller privileges can craft an environment override to hijack the Rust compiler:
Example payload to redirect RUSTC to a malicious binary export RUSTC=/path/to/malicious/executable Trigger a cargo build via OpenClaw that invokes rustc openclaw build --project vulnerable_project
Alternatively, using `CARGO_TARGET__LINKER` to load a malicious linker:
Set linker for x86_64-unknown-linux-gnu target export CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_LINKER=/path/to/malicious/linker Invoke cargo build openclaw build --target x86_64-unknown-linux-gnu
The injected executable runs with the privileges of the OpenClaw host process, leading to unauthorized command execution and potential persistence.
Protection
- Upgrade immediately: Update OpenClaw to version `2026.6.6` or later.
- Restrict access: If upgrading is not immediately possible, restrict network access to the affected environment-filtering feature so lower-trust callers cannot reach it (e.g., limit network ACLs to trusted clients only).
- Implement least privilege: Run OpenClaw processes with the minimum required privileges to reduce the impact of exploitation.
- Monitor environment variables: Deploy monitoring for anomalous environment variable changes, especially those related to build tools and interpreters.
- Apply compensating controls: Use system-level environment variable restrictions and application-level input sanitization.
Impact
- Privilege Escalation: Attackers can bypass authentication and authorization checks, executing commands with elevated privileges.
- Arbitrary Code Execution: Malicious actors can execute arbitrary code in the host context.
- Persistence: The vulnerability can be used to establish persistent backdoors, as manipulated environment settings may persist across multiple execution contexts.
- Confidentiality, Integrity, and Availability: Successful exploitation affects all three pillars of security.
- Supply Chain Risk: As OpenClaw is an npm package, compromised instances could affect downstream dependents and integrations.
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Sources:
Reported By: nvd.nist.gov
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