CVE-2016-3078 in PHP
Summary
by MITRE
Multiple integer overflows in php_zip.c in the zip extension in PHP before 7.0.6 allow remote attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact via a crafted call to (1) getFromIndex or (2) getFromName in the ZipArchive class.
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Analysis
by VulDB Data Team • 06/11/2024
The vulnerability identified as CVE-2016-3078 represents a critical security flaw within PHP's zip extension that affects versions prior to 7.0.6. This issue stems from multiple integer overflows occurring in the php_zip.c file, which serves as the core implementation for zip archive functionality within the PHP runtime environment. The vulnerability specifically targets the ZipArchive class and its methods getFromIndex and getFromName, which are commonly used for extracting data from zip archives. These integer overflows create a condition where maliciously crafted zip files can trigger memory corruption during archive processing, potentially leading to system instability or complete application crashes.
The technical nature of this vulnerability falls under the category of heap-based buffer overflow as classified by CWE-121, where insufficient integer overflow checks allow attackers to manipulate memory allocation sizes beyond intended limits. When PHP processes a malicious zip file through the vulnerable getFromIndex or getFromName methods, the integer overflows cause the application to allocate insufficient memory buffers for extracted data. This memory corruption can manifest as heap corruption, which may result in unpredictable behavior including application crashes, memory corruption, or potentially more severe consequences depending on the execution context. The vulnerability demonstrates how improper input validation and integer arithmetic handling can create exploitable conditions in application code.
The operational impact of CVE-2016-3078 extends beyond simple denial of service scenarios, as the vulnerability can potentially enable more sophisticated attacks depending on the environment where PHP is deployed. Remote attackers can leverage this vulnerability to cause application crashes, leading to service disruption and potential denial of service for legitimate users. The unspecified other impacts mentioned in the CVE description suggest that under certain conditions, this vulnerability could potentially be exploited for more serious consequences including privilege escalation or arbitrary code execution, particularly when PHP runs with elevated privileges or in environments where memory corruption can be leveraged for further exploitation. This vulnerability directly impacts the availability and integrity of web applications that rely on PHP for processing zip archives.
Mitigation strategies for CVE-2016-3078 primarily focus on upgrading to PHP version 7.0.6 or later, where the integer overflow issues have been resolved through proper input validation and bounds checking. System administrators should prioritize patching affected installations and implementing proper input sanitization for any user-provided zip files within their applications. Additional protective measures include deploying web application firewalls that can detect and block suspicious zip file content, implementing strict file type validation, and ensuring PHP applications properly validate and sanitize all input data before processing. The vulnerability aligns with ATT&CK technique T1203 (Exploitation for Client Execution) and T1499 (Endpoint Denial of Service) as it enables remote attackers to cause system instability and potentially gain unauthorized access through application-level exploitation. Organizations should also consider implementing monitoring and alerting for abnormal application behavior that may indicate exploitation attempts, particularly around zip archive processing operations.