Horizon Alert
Summary of the vulnerability and why it matters
This advisory concerns a vulnerability in a component related to data encryption, specifically affecting how authentication tags are handled. If an attacker can execute code on a system, they may be able to bypass integrity checks designed to protect encrypted data by manipulating a specific environment variable. The main concern is confirming if this specific component and its usage are relevant to your environment.
- Bypasses data integrity checks if code is executed.
- Matters if unauthenticated encrypted data is a risk.
- Confirm relevance and any exposure.
Attack Path
How an attacker could exploit the issue
An attacker who can execute code on a system may be able to bypass integrity checks. This is achieved by setting a specific environment variable, which then causes the `openssl_encrypt` function to skip the generation and verification of HMAC tags. This allows an attacker to manipulate encrypted data without detection, potentially leading to the acceptance of tampered or malicious data as legitimate.
- Attackers need code execution.
- Trigger by setting an environment variable.
- Bypasses data integrity checks.
Live Threat
Current exploitation, exposure, and threat context
When the `PYTEST_CURRENT_TEST` environment variable is set, encrypted data may lose its integrity protection because HMAC tag generation and verification are bypassed. This could allow an attacker with code execution to substitute unauthenticated ciphertext for legitimate encrypted data.
- Encrypted data integrity.
- Bypassing HMAC checks.
- Data authenticity compromised.
Operational Fix
Recommended remediation, mitigation, and detection steps
This vulnerability in openssl_encrypt, triggered by a specific environment variable, primarily affects development and testing environments. Application owners and platform teams should first identify where this library is used and whether the affected testing configurations are accessible or critical to ongoing development pipelines. Once confirmed, owners should assess the risk and plan remediation, which may involve updating the library or ensuring test environments are properly isolated and secured.
- Application owners should investigate usage.
- Verify test environment accessibility and criticality.
- Plan remediation based on assessed risk.
