CVE-2015-5243 in phpwhois
Summary
by MITRE
phpWhois allows remote attackers to execute arbitrary code via a crafted whois record.
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Analysis
by VulDB Data Team • 05/02/2023
The vulnerability identified as CVE-2015-5243 represents a critical remote code execution flaw within the phpWhois application ecosystem. This vulnerability stems from improper input validation and sanitization mechanisms within the whois record processing functionality, creating an avenue for malicious actors to inject and execute arbitrary code on affected systems. The flaw specifically manifests when the application processes whois data returned from domain registration servers, where untrusted input is directly incorporated into system operations without adequate security controls.
The technical exploitation of this vulnerability occurs through the manipulation of whois record data that phpWhois receives from various domain registrars and registry servers. When the application encounters specially crafted whois responses containing malicious payloads, it fails to properly sanitize or escape these inputs before using them in system commands or database operations. This processing error creates a path for attackers to inject shell commands or code execution directives that the application subsequently executes with the privileges of the web server process. The vulnerability is particularly dangerous because whois data is typically considered benign and is often processed automatically without extensive security scrutiny.
The operational impact of CVE-2015-5243 extends beyond simple code execution to encompass full system compromise and potential lateral movement within network environments. Attackers who successfully exploit this vulnerability can gain unauthorized access to the underlying server, potentially leading to data exfiltration, system modification, or the establishment of persistent backdoors. The vulnerability affects systems running vulnerable versions of phpWhois, which was widely deployed across web hosting environments and network monitoring applications that rely on whois data for various operational functions. Organizations utilizing these systems face significant risk exposure, particularly those with limited security monitoring and patch management capabilities.
Security mitigations for CVE-2015-5243 should focus on immediate patch application and input validation enhancements. Organizations must ensure they are running patched versions of phpWhois that address the specific input sanitization flaws. Network segmentation and access controls should be implemented to limit whois data processing to trusted sources only. The implementation of proper input validation frameworks, including regular expression filtering and escape sequence handling, can prevent malicious payloads from being executed. Additionally, monitoring systems should be deployed to detect anomalous whois data processing patterns and unusual command execution activities. This vulnerability aligns with CWE-74, which addresses improper neutralization of special elements in output used by a downstream component, and maps to ATT&CK technique T1059 for command and scripting interpreter, highlighting the critical nature of input validation in preventing remote code execution attacks.