CVE-2006-1015 in PHP
Summary
by MITRE
Argument injection vulnerability in certain PHP 3.x, 4.x, and 5.x applications, when used with sendmail and when accepting remote input for the additional_parameters argument to the mail function, allows remote attackers to read and create arbitrary files via the sendmail -C and -X arguments. NOTE: it could be argued that this is a class of technology-specific vulnerability, instead of a particular instance; if so, then this should not be included in CVE.
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Analysis
by VulDB Data Team • 06/08/2025
The vulnerability described in CVE-2006-1015 represents a critical argument injection flaw affecting PHP versions 3.x through 5.x when integrated with sendmail functionality. This issue arises from insufficient input validation within the mail function's additional_parameters argument, creating a pathway for malicious actors to manipulate command execution through carefully crafted input sequences. The vulnerability specifically targets applications that process remote input and subsequently pass it to the mail function without proper sanitization, making it particularly dangerous in web applications that handle user-submitted data.
The technical exploitation of this vulnerability leverages the sendmail command-line interface through the -C and -X arguments, which are typically used for configuration file specification and debugging output redirection respectively. Attackers can inject these arguments into the additional_parameters parameter, effectively bypassing normal security boundaries and gaining unauthorized access to file system operations. The -C argument allows attackers to specify configuration files that may contain sensitive information or provide access to system resources, while the -X argument enables arbitrary file creation or modification through log file redirection. This exploitation pattern aligns with CWE-77 and CWE-78 categories, specifically addressing command injection vulnerabilities where user-controllable input is directly incorporated into system commands without proper validation or escaping mechanisms.
The operational impact of this vulnerability extends beyond simple file access, as it can enable attackers to execute arbitrary code on the affected system, potentially leading to complete system compromise. Remote attackers can use this vulnerability to read sensitive files that may contain database credentials, application configuration details, or other confidential information stored on the server. Additionally, the ability to create arbitrary files through the -X argument opens possibilities for establishing persistence mechanisms, uploading malicious payloads, or conducting further reconnaissance activities. This vulnerability particularly affects web applications that utilize PHP mail functions for user notifications, contact forms, or automated email processing, making it a significant concern for organizations maintaining web-facing services.
Mitigation strategies for CVE-2006-1015 require immediate attention through multiple defensive layers. The most effective approach involves upgrading to newer PHP versions that address this vulnerability through improved input validation and parameter handling within the mail function. Organizations should also implement strict input sanitization measures, particularly for any user-provided data that may be passed to mail function parameters. The principle of least privilege should be applied by configuring sendmail with restricted permissions and limiting the system's ability to access sensitive files. Network-level protections such as firewalls and intrusion detection systems can help monitor for suspicious command execution patterns. Additionally, the ATT&CK framework categorizes this vulnerability under T1059.007 for command and scripting interpreter and T1078 for valid accounts, emphasizing the need for comprehensive monitoring of command execution and access patterns to detect potential exploitation attempts. Regular security audits and penetration testing should be conducted to identify and remediate similar vulnerabilities in legacy PHP applications that cannot be immediately upgraded.