CVE-2009-3045 in Web Browser
Summary
by MITRE
Opera before 10.00 trusts root X.509 certificates signed with the MD2 algorithm, which makes it easier for man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted server certificate.
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Analysis
by VulDB Data Team • 03/08/2025
The vulnerability described in CVE-2009-3045 represents a critical cryptographic weakness in Opera web browsers prior to version 10.00 that fundamentally undermines secure communication protocols. This flaw stems from the browser's acceptance of X.509 certificates signed using the MD2 cryptographic hash algorithm, which was deprecated decades ago due to severe security vulnerabilities. The MD2 algorithm suffers from collision resistance issues and has been widely recognized as cryptographically broken since the early 2000s, making it trivial for attackers to generate fraudulent certificates that appear legitimate to affected browsers. This weakness directly violates industry security standards and best practices established by organizations such as NIST and the IETF, which have explicitly recommended against using MD2 for certificate signing since 2005.
The technical implementation flaw in Opera's certificate validation process creates a dangerous trust relationship that allows malicious actors to perform man-in-the-middle attacks with minimal effort. When an attacker generates a certificate signed with MD2 and presents it to an affected Opera browser, the browser will accept it as valid due to its outdated trust model. This vulnerability specifically targets the SSL/TLS certificate verification mechanism, where the browser should reject certificates signed with deprecated or weak cryptographic algorithms. The attack vector is particularly insidious because it requires no sophisticated techniques or expensive computational resources - an attacker simply needs to create a certificate that appears to be from a legitimate authority, which becomes possible when MD2 signatures are accepted. This represents a clear violation of the principle of least privilege and certificate validation integrity that security frameworks like the CA/Browser Forum and RFC 5280 mandate for secure certificate handling.
The operational impact of this vulnerability extends far beyond simple browser security concerns, as it fundamentally compromises the confidentiality and integrity of all SSL/TLS communications within the affected browser environment. Any user of Opera versions prior to 10.00 becomes susceptible to impersonation attacks where attackers can intercept and modify encrypted communications between the browser and web servers. This includes sensitive activities such as banking transactions, email communications, and corporate data transfers that rely on SSL/TLS encryption for protection. The vulnerability creates a persistent threat vector that remains active as long as the affected browser version is in use, making it particularly dangerous in enterprise environments where legacy browser support is maintained. According to the MITRE ATT&CK framework, this vulnerability maps to the T1552.001 technique for "Unsecured Credentials" and represents a critical weakness in the credential validation process that enables broader attack chains.
The recommended mitigation strategy for CVE-2009-3045 involves immediate upgrade to Opera version 10.00 or later, which properly implements certificate validation that rejects MD2-signed certificates. Organizations should also implement network monitoring to detect potential certificate manipulation attempts and consider deploying additional security controls such as certificate pinning for critical applications. The vulnerability demonstrates the importance of maintaining up-to-date cryptographic standards and the dangers of supporting deprecated algorithms in security-critical software components. Security professionals should also review their certificate management policies to ensure that only certificates signed with strong cryptographic algorithms such as SHA-256 or SHA-384 are accepted. This vulnerability serves as a cautionary example of how legacy support can create security risks and emphasizes the need for regular security assessments and vulnerability management programs that address both known and emerging cryptographic threats. The remediation process should include comprehensive testing to ensure that the upgrade does not break legitimate certificate validation requirements while maintaining strong cryptographic security standards.