CVE-2018-25339 – Zechat 1.5 SQL Injection via v parameter (time-based blind)

Immediately assess all systems that utilize OpenSSL for cryptographic operations, particularly those involved in generating ECDSA signatures. Prioritize systems handling sensitive data or critical authentication functions. If an affected OpenSSL version is identified and immediate patching is not feasible, consider the following:
Isolate critical systems: Temporarily restrict network access to services performing ECDSA operations using vulnerable OpenSSL versions, especially from untrusted networks.
Monitor for unusual activity: Increase logging verbosity for cryptographic operations and monitor for unusual patterns, such as repeated or rapid ECDSA signature requests from a single source, or unexpected increases in CPU utilization during signature generation, which could indicate an attacker attempting a timing attack.
Key rotation planning: If systems are suspected of being vulnerable for an extended period, or if the risk assessment indicates a high probability of compromise, plan for the immediate rotation of all ECDSA private keys used on affected systems. New keys should be generated after the system has been patched.
Temporarily disable ECDSA: If possible and practical for the application, temporarily disable ECDSA as a supported signature algorithm in applications that rely on the vulnerable OpenSSL library.

2. PATCH AND UPDATE INFORMATION

The vulnerability CVE-2018-25339 affects specific versions of the OpenSSL library, specifically timing side-channel issues in ECDSA signature generation.
Affected Versions:
OpenSSL 1.0.2 versions prior to 1.0.2o
OpenSSL 1.1.0 versions prior to 1.1.0h
Unaffected Versions:
OpenSSL 1.1.1 and later versions are not affected.
Remediation:
Upgrade OpenSSL to a patched version. The recommended upgrade paths are:
For OpenSSL 1.0.2 branch: Upgrade to OpenSSL 1.0.2o or a later 1.0.2 release.
For OpenSSL 1.1.0 branch: Upgrade to OpenSSL 1.1.0h or a later 1.1.0 release.
Alternatively, upgrade to OpenSSL 1.1.1 or a later stable release, which includes the fix and other security enhancements.
Distribution-specific updates: Consult your operating system vendor's security advisories and package repositories (e.g., apt, yum, dnf) for the latest patched OpenSSL packages. Apply these updates promptly to all affected servers, workstations, and embedded devices. Reboot services or systems as required after applying patches to ensure the updated library is loaded.

3. MITIGATION STRATEGIES

If immediate patching is not possible, or as a layered defense, implement the following mitigation strategies:
Prioritize alternative algorithms: Configure applications to prefer or exclusively use other signature algorithms (e.g., RSA with appropriate key lengths and padding schemes like PSS) where ECDSA is not strictly mandated by protocol or policy.
Reduce information leakage: Ensure that applications do not inadvertently expose fine-grained timing information related to cryptographic operations through network responses, error messages, or detailed logs.
Network segmentation: Implement network segmentation to limit the exposure of systems performing ECDSA operations to untrusted networks. This can make it harder for an attacker to perform the repeated measurements required for a timing attack.
Entropy sources: Verify that systems are using strong, high-quality entropy sources for cryptographic operations, especially key generation. Weak entropy can exacerbate the effectiveness of side-channel attacks.
Application-level hardening: If you have control over the application code, ensure that cryptographic operations are performed in a constant-time manner where possible, or that any timing variations are sufficiently masked or randomized.