CVE-2003-0192 in HTTP Server
Summary
by MITRE
Apache 2 before 2.0.47, and certain versions of mod_ssl for Apache 1.3, do not properly handle "certain sequences of per-directory renegotiations and the SSLCipherSuite directive being used to upgrade from a weak ciphersuite to a strong one," which could cause Apache to use the weak ciphersuite.
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Analysis
by VulDB Data Team • 03/08/2021
This vulnerability resides in the Apache HTTP Server and mod_ssl module implementations where improper handling of SSL/TLS renegotiation sequences creates a security weakness that allows attackers to downgrade encryption strength. The flaw specifically affects Apache 2.0 versions prior to 2.0.47 and certain Apache 1.3 mod_ssl versions, where the server fails to correctly process scenarios involving per-directory SSL renegotiations combined with the SSLCipherSuite directive. When an attacker can manipulate the sequence of SSL negotiations and cipher suite specifications, the server may inadvertently revert to using weaker cryptographic ciphers than intended, undermining the security of encrypted communications.
The technical mechanism of this vulnerability involves the interaction between SSL renegotiation protocols and cipher suite configuration directives within Apache's SSL implementation. During SSL handshakes, when Apache processes multiple directory-level configurations and encounters a scenario where a weak cipher suite is initially negotiated followed by a directive to upgrade to a stronger suite, the server's logic fails to properly enforce the upgrade. This creates an opportunity for man-in-the-middle attacks where an attacker can force the connection to use weaker cryptographic algorithms, potentially making it easier to intercept or modify encrypted traffic. The vulnerability is categorized under CWE-310 as "Cryptographic Issues" and represents a failure in proper cryptographic implementation.
The operational impact of this vulnerability is significant as it allows attackers to downgrade encryption strength without requiring authentication or complex attack vectors. Systems running affected Apache versions become susceptible to cryptographic downgrade attacks that can compromise the confidentiality and integrity of transmitted data. Network traffic that should be protected by strong encryption may instead use weak ciphers, making it vulnerable to various attacks including session hijacking, data interception, and cryptographic analysis. This weakness particularly affects web applications that rely on Apache's SSL capabilities for secure communication, potentially exposing sensitive information to unauthorized parties.
Mitigation strategies for this vulnerability include immediate patching of Apache installations to versions 2.0.47 or later for Apache 2.0, and updating to appropriate mod_ssl versions for Apache 1.3 environments. Organizations should also implement proper SSL configuration practices that minimize the use of per-directory renegotiation directives and ensure consistent cipher suite specifications throughout the server configuration. Network administrators should monitor for unusual SSL negotiation patterns and implement security controls that prevent downgrade attacks. Additionally, organizations should consider implementing automated patch management systems to ensure timely deployment of security updates. The vulnerability demonstrates the importance of proper cryptographic protocol implementation and highlights the need for comprehensive testing of SSL/TLS configurations in production environments. This issue aligns with ATT&CK technique T1566.001 for credential access through network sniffing and T1071.001 for application layer protocol usage, as it affects the fundamental security of encrypted communications and can be exploited to compromise network security.