CVE-2008-0786 in Cacti
Summary
by MITRE
CRLF injection vulnerability in Cacti 0.8.7 before 0.8.7b and 0.8.6 before 0.8.6k, when running on older PHP interpreters, allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via unspecified vectors.
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Analysis
by VulDB Data Team • 08/07/2019
The CVE-2008-0786 vulnerability represents a critical CRLF injection flaw affecting Cacti monitoring software versions prior to specific patch releases. This vulnerability specifically impacts installations running on older PHP interpreters where the application fails to properly sanitize user input before processing HTTP headers. The flaw enables remote attackers to inject malicious carriage return and line feed characters into HTTP responses, creating a pathway for sophisticated attack vectors that can compromise the integrity of web communications. The vulnerability exists due to inadequate input validation mechanisms within the application's header processing routines, which were not sufficiently hardened against control character injection attacks.
The technical exploitation of this vulnerability stems from the application's failure to properly escape or filter special characters during HTTP header construction. When user-supplied data containing CRLF sequences is processed without proper sanitization, attackers can inject additional HTTP headers into the response stream. This creates opportunities for HTTP response splitting attacks where malicious headers can be injected to redirect users, inject malicious content, or manipulate browser behavior. The vulnerability is particularly dangerous because it operates at the HTTP protocol level, affecting the fundamental communication between web servers and clients. Attackers can leverage this flaw to perform session hijacking, cache poisoning, or cross-site scripting attacks by manipulating the HTTP response headers that control browser behavior and content delivery.
The operational impact of CVE-2008-0786 extends beyond simple data corruption or unauthorized access, as it fundamentally compromises the trust model between web applications and their users. Organizations utilizing vulnerable Cacti installations face risks including unauthorized access to monitoring data, potential data exfiltration, and the ability for attackers to manipulate the monitoring environment itself. This vulnerability directly violates security principles outlined in CWE-113, which addresses improper neutralization of CRLF sequences in HTTP headers. The attack surface is particularly concerning for network monitoring environments where Cacti is commonly deployed, as these systems often contain sensitive infrastructure data and may serve as attack vectors for broader network compromise. The vulnerability's exploitation capability aligns with ATT&CK technique T1190, which covers exploitation of remote services through injection attacks.
Mitigation strategies for this vulnerability require immediate patching of affected Cacti installations to versions 0.8.7b or 0.8.6k and later, which contain proper input validation and sanitization routines. System administrators should also implement network-level protections such as web application firewalls that can detect and block CRLF injection attempts, though these should not be considered primary defenses. Input validation should be enhanced at multiple layers including application-level sanitization, database input filtering, and network-level header inspection. Organizations should conduct comprehensive vulnerability assessments to identify all instances of vulnerable Cacti installations and ensure proper configuration of PHP interpreters to prevent similar injection vulnerabilities. The remediation process must include thorough testing of patched applications to ensure that legitimate functionality remains intact while the security vulnerability is eliminated. Additionally, implementing proper security monitoring and logging of HTTP traffic can help detect potential exploitation attempts and provide forensic evidence for incident response activities.