CVE-2009-0130 in OpenSSL
Summary
by MITRE
** DISPUTED ** lib/crypto/c_src/crypto_drv.c in erlang does not properly check the return value from the OpenSSL DSA_do_verify function, which might allow remote attackers to bypass validation of the certificate chain via a malformed SSL/TLS signature, a similar vulnerability to CVE-2008-5077. NOTE: a package maintainer disputes this issue, reporting that there is a proper check within the only code that uses the applicable part of crypto_drv.c, and thus "this report is invalid."
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Analysis
by VulDB Data Team • 01/21/2025
The vulnerability described in CVE-2009-0130 relates to a potential security flaw in the Erlang programming language's cryptographic implementation, specifically within the crypto_drv.c file located in the lib/crypto/c_src directory. This issue involves the OpenSSL DSA_do_verify function which is responsible for validating digital signatures within SSL/TLS certificate chains. The vulnerability arises from what appears to be a missing or inadequate return value check, potentially allowing malicious actors to bypass critical certificate validation mechanisms. This represents a significant concern for systems relying on Erlang's cryptographic capabilities for secure communications, as it could enable man-in-the-middle attacks or certificate forgery scenarios where malformed signatures might be accepted as valid.
The technical flaw stems from improper error handling within the cryptographic verification process, where the return value from OpenSSL's DSA_do_verify function is not being properly validated. This function is designed to verify digital signatures against public keys, and when it fails to return an expected result, the calling code should reject the signature. However, in this case, the Erlang implementation appears to proceed with signature validation regardless of the verification function's outcome. The vulnerability operates at the intersection of cryptographic protocol implementation and software security, where a single missing error check can undermine the entire certificate validation chain. This type of flaw falls under CWE-252, which specifically addresses "Unchecked Return Value" conditions that can lead to security vulnerabilities when error conditions are not properly handled.
From an operational perspective, this vulnerability could have severe implications for systems using Erlang-based applications that implement SSL/TLS security protocols. Attackers could potentially craft malformed SSL/TLS signatures that would be accepted by vulnerable systems, effectively bypassing the certificate chain validation that normally ensures the authenticity of TLS connections. The impact would be particularly significant in environments where Erlang is used for building secure communication systems, web servers, or applications handling sensitive data. The vulnerability's similarity to CVE-2008-5077 suggests a pattern of inadequate error handling in cryptographic libraries, where the same class of issues can manifest across different implementations. This type of vulnerability would typically be classified under the ATT&CK technique T1552.004 for "Credentials in Files" or T1046 for "Network Service Scanning" when exploited in conjunction with other attack vectors.
The reported dispute from the package maintainer regarding the validity of this CVE highlights the complexity of cryptographic vulnerability assessment and the challenges in determining whether a reported issue actually represents a real security risk. The maintainer's claim that proper checks exist within the code that uses the affected crypto_drv.c functionality suggests that either the vulnerability description is incomplete or the issue has been addressed in subsequent code revisions. This dispute reflects common challenges in security research where the line between theoretical vulnerability and practical exploitability can be blurred, especially in complex cryptographic implementations. Organizations should consider this vulnerability as potentially relevant to their security posture while also acknowledging the disputed nature of the report. The recommended approach would involve verifying the actual implementation within specific Erlang versions and ensuring that all cryptographic verification functions properly validate their return values, following the principle of defensive programming and proper error handling in security-critical code sections.
The broader implications of this vulnerability extend beyond the immediate technical flaw to highlight the importance of rigorous code review processes in cryptographic implementations. This case demonstrates how seemingly minor issues in error handling can have significant security consequences, particularly in security-sensitive contexts like certificate validation. The cryptographic community should remain vigilant about similar issues in other implementations and ensure that all return values from cryptographic functions are properly validated. Additionally, the dispute surrounding this CVE underscores the need for clear communication between security researchers and software maintainers to properly assess and validate reported vulnerabilities, as the distinction between a genuine security issue and a false positive can be critical for proper risk management and remediation planning.