CVE-2012-2675 in nedmalloc
Summary
by MITRE
Multiple integer overflows in the (1) CallMalloc (malloc) and (2) nedpcalloc (calloc) functions in nedmalloc (nedmalloc.c) before 1.10 beta2 make it easier for context-dependent attackers to perform memory-related attacks such as buffer overflows via a large size value, which causes less memory to be allocated than expected.
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Analysis
by VulDB Data Team • 12/07/2021
The vulnerability identified as CVE-2012-2675 represents a critical memory management flaw within the nedmalloc memory allocator library, specifically affecting the CallMalloc and nedpcalloc functions. This issue manifests as integer overflows that occur when processing large size values during memory allocation operations. The flaw stems from inadequate input validation and overflow checking within the memory allocation routines, creating a scenario where attackers can manipulate the allocation process to reserve insufficient memory while appearing to request substantial amounts. Such behavior creates a dangerous condition where the system allocates less memory than required for legitimate operations, leaving the application vulnerable to subsequent memory corruption attacks.
The technical implementation of this vulnerability involves the manipulation of integer variables used to calculate memory allocation sizes. When attackers provide large size parameters to the affected functions, the integer overflow causes the calculated allocation size to wrap around to a much smaller value. This occurs because the integer arithmetic does not properly check for overflow conditions before performing the calculation. The vulnerability specifically affects the nedmalloc.c implementation where the malloc and calloc functions are implemented, with the issue persisting in versions prior to 1.10 beta2. The flaw operates under the principle that when integer overflow occurs in memory allocation calculations, the resulting smaller allocation size creates opportunities for attackers to exploit memory boundaries and potentially execute arbitrary code.
From an operational perspective, this vulnerability creates significant risks for applications that rely on nedmalloc for memory management. Context-dependent attackers can leverage this flaw to perform memory-related attacks including buffer overflows, which may lead to arbitrary code execution, denial of service conditions, or information disclosure. The impact extends beyond simple memory corruption as the insufficient allocation allows attackers to overwrite adjacent memory regions or manipulate data structures that depend on proper memory layout. This vulnerability particularly affects systems where memory allocation is heavily utilized and where applications may be exposed to untrusted input through network services or file processing operations. The attack vector requires the ability to control allocation size parameters, making it more likely to be exploited in applications that accept user-supplied memory requests or process untrusted data streams.
The vulnerability aligns with CWE-190, which describes integer overflow and underflow conditions, and specifically relates to the broader category of memory safety issues. From an ATT&CK framework perspective, this vulnerability maps to techniques involving memory corruption and privilege escalation through exploitation of memory management flaws. The remediation strategy focuses on updating to nedmalloc version 1.10 beta2 or later, which implements proper integer overflow checks and validation mechanisms. Additionally, developers should implement input sanitization for allocation parameters, employ static analysis tools to detect potential integer overflow conditions, and consider using memory-safe programming practices. System administrators should monitor for applications using vulnerable versions of nedmalloc and ensure regular updates are applied. The fix typically involves adding proper bounds checking before integer arithmetic operations and implementing overflow detection mechanisms that prevent the wraparound behavior that enables the attack vector. Organizations should also implement runtime protections such as address space layout randomization and stack canaries to mitigate potential exploitation attempts.