CVE-2017-12613 in macOS
Summary
by MITRE
When apr_time_exp*() or apr_os_exp_time*() functions are invoked with an invalid month field value in Apache Portable Runtime APR 1.6.2 and prior, out of bounds memory may be accessed in converting this value to an apr_time_exp_t value, potentially revealing the contents of a different static heap value or resulting in program termination, and may represent an information disclosure or denial of service vulnerability to applications which call these APR functions with unvalidated external input.
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Analysis
by VulDB Data Team • 10/08/2025
The vulnerability identified as CVE-2017-12613 resides within the Apache Portable Runtime library, specifically affecting versions 1.6.2 and earlier. This flaw manifests when the apr_time_exp() or apr_os_exp_time() functions process invalid month field values, creating a condition where out-of-bounds memory access occurs during the conversion process to apr_time_exp_t structures. The issue represents a classic buffer over-read scenario that can be exploited through improper input validation, particularly when applications utilize these functions with unvalidated external data sources.
The technical implementation of this vulnerability stems from inadequate bounds checking within the time conversion routines of APR. When developers pass invalid month values to these functions, the underlying code fails to properly validate the input parameters before proceeding with memory operations. The apr_time_exp_t structure contains multiple fields including month, day, hour, minute, and second values that are processed through mathematical calculations and array indexing operations. When an invalid month value is provided, typically outside the expected range of 0-11, the conversion logic attempts to access memory locations that extend beyond the allocated bounds of the internal data structures.
This vulnerability presents significant operational risks to applications relying on APR for time processing functions. The potential impacts include information disclosure through memory leaks, where adjacent heap values may be exposed to attackers, and denial of service conditions that can cause application crashes or termination. The information disclosure aspect aligns with CWE-125, which describes out-of-bounds read vulnerabilities, while the potential for denial of service maps to CWE-400, covering unchecked resource consumption. From an adversarial perspective, this vulnerability can be leveraged through the ATT&CK technique of resource exhaustion or information gathering, particularly when attackers can control input parameters to these functions.
Applications that process external time data, such as web servers, logging systems, or any software utilizing APR for time manipulation, face the highest risk from this vulnerability. The exploitability is enhanced when these functions receive unvalidated user input, such as timestamps from HTTP headers, log entries, or API requests. Security professionals should consider this vulnerability as part of broader input validation assessments, particularly when evaluating applications that utilize APR components. The remediation strategy focuses on upgrading to APR versions 1.6.3 or later, where the bounds checking has been properly implemented to prevent out-of-bounds memory access. Additionally, developers should implement defensive programming practices including input validation, parameter sanitization, and proper error handling when invoking these time conversion functions to mitigate potential exploitation scenarios.