CVE-2017-7529 in Xcode
Summary
by MITRE
Nginx versions since 0.5.6 up to and including 1.13.2 are vulnerable to integer overflow vulnerability in nginx range filter module resulting into leak of potentially sensitive information triggered by specially crafted request.
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Analysis
by VulDB Data Team • 11/10/2024
The vulnerability identified as CVE-2017-7529 represents a critical integer overflow flaw within the nginx range filter module that affects a substantial portion of the nginx web server ecosystem. This vulnerability exists in nginx versions ranging from 0.5.6 through 1.13.2, creating a widespread impact across numerous deployments that rely on this popular web server software. The integer overflow occurs specifically within the range filter processing mechanism, which is responsible for handling HTTP range requests that allow clients to request specific portions of a file or resource. The flaw manifests when nginx processes specially crafted HTTP range requests that contain malformed or excessively large range values, causing the internal integer arithmetic to overflow beyond the maximum representable value for the data type being used.
The technical exploitation of this vulnerability stems from the improper handling of integer values within the range filter module's processing logic. When a malicious client sends a request containing a crafted range specification that exceeds the maximum value that can be represented by the integer data type, the system experiences an integer overflow condition. This overflow causes the range processing logic to behave unpredictably, potentially leading to memory corruption or incorrect boundary calculations. The vulnerability specifically impacts how nginx handles the conversion and validation of range request parameters, where the system fails to properly validate the input values before performing arithmetic operations that could result in overflow conditions.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks depending on the deployment environment. When an integer overflow occurs during range request processing, it can result in memory layout corruption that may leak sensitive information from adjacent memory regions. This information leakage could include memory addresses, configuration data, user session information, or other potentially sensitive data that resides in memory adjacent to the vulnerable processing functions. The vulnerability creates a pathway for attackers to potentially gather intelligence about the system's memory layout and internal state, which could be leveraged in subsequent exploitation attempts. According to CWE classification, this vulnerability maps to CWE-191 Integer Underflow or Overflow, specifically representing an integer overflow condition that leads to information disclosure.
The exploitation of CVE-2017-7529 aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to reconnaissance and initial access phases. Attackers can utilize this vulnerability as part of their information gathering process to understand the target environment better before launching more sophisticated attacks. The vulnerability's impact on information disclosure makes it particularly useful for attackers seeking to map memory layouts or extract sensitive data that could aid in privilege escalation or further exploitation. Security professionals should note that this vulnerability demonstrates the importance of proper input validation and integer arithmetic handling in web server software, as even seemingly benign HTTP request processing can become a vector for information leakage when proper bounds checking is absent.
Organizations affected by this vulnerability should prioritize immediate patching of their nginx installations to version 1.13.3 or later, which contains the necessary fixes for the integer overflow condition. The mitigation strategy should include comprehensive testing of the patched environment to ensure that legitimate range request functionality remains intact while eliminating the overflow vulnerability. System administrators should also implement monitoring for unusual range request patterns that might indicate exploitation attempts, as these requests may be flagged by security tools or intrusion detection systems. The vulnerability underscores the critical importance of maintaining up-to-date software versions and implementing robust input validation mechanisms, particularly in core infrastructure components like web servers that handle diverse and potentially malicious input from external sources. Additionally, network segmentation and access controls should be reviewed to limit potential impact should exploitation occur, as the information disclosure aspect of this vulnerability could provide attackers with valuable reconnaissance data for targeting other system components.