CVE-2004-2761 in Trace File Analyzer
Summary
by MITRE
The MD5 Message-Digest Algorithm is not collision resistant, which makes it easier for context-dependent attackers to conduct spoofing attacks, as demonstrated by attacks on the use of MD5 in the signature algorithm of an X.509 certificate.
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Analysis
by VulDB Data Team • 05/28/2026
The vulnerability described in CVE-2004-2761 fundamentally undermines the security assurances provided by the MD5 cryptographic hash function, which has profound implications for digital security infrastructure. This weakness stems from the inherent design flaws within the MD5 algorithm that make it susceptible to collision attacks, where two different inputs can produce identical hash outputs. The vulnerability specifically targets the use of MD5 in X.509 certificate signature algorithms, which are critical components of public key infrastructure that establish trust relationships between entities in secure communications. When attackers can generate colliding hash values, they can potentially create fraudulent certificates that appear legitimate to systems relying on MD5-based signature verification, thereby compromising the integrity and authenticity guarantees that digital certificates are designed to provide.
The technical flaw exploited in this vulnerability resides in the mathematical weaknesses of the MD5 algorithm's compression function, which was discovered through extensive cryptanalytic research. The MD5 algorithm processes input data in 512-bit blocks and produces a 128-bit hash value, but its internal structure contains vulnerabilities that allow attackers to find two distinct messages that will produce the same hash output. This collision resistance failure means that an attacker can craft two different certificate requests that will generate identical MD5 signatures, enabling them to impersonate legitimate certificate authorities or bypass authentication mechanisms that rely on MD5 checksums. The vulnerability operates within the context-dependent attack model where the attacker requires specific conditions to exploit the weakness, such as access to the certificate generation process or the ability to influence the signing process.
The operational impact of this vulnerability extends far beyond simple cryptographic weakness, as it fundamentally compromises the trust model that underpins secure communications and digital identity verification. When MD5 is used in X.509 certificate signature algorithms, systems that validate these certificates become vulnerable to spoofing attacks where malicious actors can create forged certificates that will be accepted as legitimate by systems using MD5-based validation. This affects web browsers, email clients, and other security applications that rely on certificate validation to establish secure connections and verify identities. The implications are particularly severe because X.509 certificates are used extensively for secure web browsing through SSL/TLS protocols, email encryption, code signing, and various enterprise security applications. The vulnerability creates a pathway for man-in-the-middle attacks, certificate forgery, and authentication bypass scenarios that can compromise entire security infrastructures.
Security professionals should recognize this vulnerability as a direct violation of the cryptographic security requirements established in industry standards such as those defined by NIST and ISO/IEC 14443, where the use of weak hash functions like MD5 is explicitly discouraged for security-critical applications. The vulnerability aligns with ATT&CK technique T1552.003, which covers "Credentials from Password Stores," as compromised certificates can provide attackers with unauthorized access to systems and services. Organizations must implement immediate mitigations including the replacement of MD5-based certificate signature algorithms with stronger alternatives such as SHA-256 or SHA-3, the implementation of certificate pinning mechanisms, and the deployment of security monitoring to detect potential certificate forgery attempts. Additionally, systems should be configured to reject certificates signed with MD5 or other weak hash algorithms, and certificate authorities should be updated to enforce stronger cryptographic requirements for all issued certificates. The remediation process requires comprehensive assessment of existing certificate infrastructure and the implementation of robust cryptographic policies that align with current security best practices and regulatory compliance requirements.