CVE-2015-3406 in Module::Signature
Summary
by MITRE
The PGP signature parsing in Module::Signature before 0.74 allows remote attackers to cause the unsigned portion of a SIGNATURE file to be treated as the signed portion via unspecified vectors.
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Analysis
by VulDB Data Team • 11/25/2024
The vulnerability identified as CVE-2015-3406 resides within the Module::Signature Perl module version 0.73 and earlier, representing a critical flaw in cryptographic signature validation mechanisms. This issue specifically affects the parsing of PGP signatures used in Perl module distribution systems, where the security of software supply chains relies heavily on proper signature verification to ensure integrity and authenticity of distributed packages.
The technical flaw manifests in the improper handling of SIGNATURE files during PGP signature verification processes. When a module signature is parsed, the vulnerability allows attackers to manipulate the unsigned portion of the SIGNATURE file in such a way that it gets incorrectly interpreted as the signed portion of the document. This manipulation occurs through unspecified vectors that exploit weaknesses in the signature parsing logic, effectively bypassing the cryptographic validation checks that should prevent such substitution attacks. The vulnerability essentially creates a scenario where an attacker can inject malicious content into what appears to be a legitimate signed package, as the unsigned section becomes incorrectly treated as the signed component.
This flaw has significant operational impact on software distribution systems that rely on Module::Signature for verifying Perl module integrity. Attackers could potentially compromise entire software supply chains by injecting malicious code into unsigned portions of SIGNATURE files, which would then be accepted as valid signatures. The attack vector allows for code injection that bypasses traditional security controls, potentially leading to remote code execution on systems that install the compromised modules. This vulnerability directly impacts the trust model of Perl module repositories, where users expect that signed modules have not been tampered with since they were signed.
The vulnerability maps to CWE-295 which describes improper certificate validation, and aligns with ATT&CK technique T1553.004 related to subvert trust controls. Organizations using affected versions of Module::Signature should immediately upgrade to version 0.74 or later to remediate this issue. Additional mitigations include implementing multi-layered verification processes, using alternative signature validation mechanisms, and conducting thorough security audits of software distribution pipelines. The incident highlights the importance of proper cryptographic implementation and the critical need for robust signature parsing logic in software supply chain security systems. This vulnerability demonstrates how seemingly minor flaws in cryptographic validation can have far-reaching consequences in software distribution security, emphasizing the necessity of comprehensive security testing for cryptographic components in critical infrastructure software.