CVE-2019-14872 in libc Library
Summary
by MITRE
The _dtoa_r function of the newlib libc library, prior to version 3.3.0, performs multiple memory allocations without checking their return value. This could result in NULL pointer dereference.
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Analysis
by VulDB Data Team • 08/26/2025
The vulnerability identified as CVE-2019-14872 resides within the newlib libc library implementation, specifically affecting versions prior to 3.3.0. This flaw manifests in the _dtoa_r function which is responsible for converting double-precision floating-point numbers to decimal string representations. The issue stems from inadequate error handling during memory allocation operations, creating a critical pathway for potential system instability and exploitation. The function's failure to validate allocation results creates a scenario where subsequent operations may attempt to dereference NULL pointers, leading to application crashes or more severe consequences.
The technical root cause of this vulnerability aligns with CWE-704, which categorizes improper handling of memory allocation failures as a weakness in software design. The _dtoa_r function performs multiple memory allocation calls throughout its execution flow without implementing proper validation checks for each allocation result. When memory allocation fails, the function continues execution assuming successful allocation, ultimately leading to NULL pointer dereference when attempting to access the failed allocation. This pattern represents a classic example of resource leak and improper error handling that can be exploited by malicious actors to disrupt normal system operations.
From an operational perspective, this vulnerability presents significant risks to systems relying on newlib libc for floating-point number conversions. The impact extends beyond simple application crashes to potentially enable more sophisticated attack vectors including denial of service conditions that could affect critical infrastructure components. Systems utilizing embedded environments or custom applications built with newlib are particularly vulnerable since these environments often lack the robust error handling mechanisms found in more comprehensive libc implementations. The vulnerability's exploitation potential increases when the affected library is used in network services or applications handling untrusted input data that could trigger the problematic code path.
The ATT&CK framework categorizes this vulnerability under T1499.004 which covers "Endpoint Denial of Service" techniques, as the memory allocation failure can lead to system instability and service disruption. Organizations should prioritize updating their newlib libc installations to version 3.3.0 or later to mitigate this risk. Additionally, implementing runtime checks for memory allocation failures in custom code that interfaces with affected libraries can provide temporary protection. Security teams should monitor for any exploitation attempts targeting this vulnerability in their network traffic and application logs, as the null pointer dereference behavior can be detected through proper system monitoring and intrusion detection systems. The remediation process should include comprehensive testing of updated libraries to ensure no regressions in application functionality while maintaining the security improvements achieved through proper memory allocation validation.