CVE-2016-5011 in util-linux
Summary
by MITRE
The parse_dos_extended function in partitions/dos.c in the libblkid library in util-linux allows physically proximate attackers to cause a denial of service (memory consumption) via a crafted MSDOS partition table with an extended partition boot record at zero offset.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/29/2024
The vulnerability identified as CVE-2016-5011 resides within the libblkid library component of util-linux, specifically in the parse_dos_extended function located in partitions/dos.c. This flaw represents a classic memory consumption denial of service vulnerability that can be exploited by attackers positioned in close physical proximity to target systems. The issue manifests when the library processes a crafted MSDOS partition table containing an extended partition boot record at zero offset, creating a scenario where the parsing routine consumes excessive memory resources without proper bounds checking or validation mechanisms.
The technical implementation of this vulnerability stems from inadequate input validation within the partition table parsing logic. When libblkid encounters a malformed MSDOS partition table structure with an extended boot record at offset zero, the parse_dos_extended function enters an infinite loop or significantly amplifies memory allocation patterns. This occurs because the function fails to properly validate the partition table structure before attempting to parse extended partition entries, leading to unbounded memory consumption that can exhaust system resources and ultimately result in system instability or complete denial of service for legitimate operations requiring disk I/O.
From an operational impact perspective, this vulnerability poses significant risks to systems that rely on libblkid for disk partition analysis and identification. The remote code execution potential is limited to physically proximate attackers who can manipulate partition table structures, making this a vector that requires physical access or network-level manipulation of storage devices. The vulnerability affects systems using util-linux versions prior to 2.28, where the memory consumption issue remains unaddressed. Security implications extend beyond simple denial of service as the memory exhaustion can potentially impact system stability, application availability, and overall operational continuity in environments where disk management operations are frequent or critical.
The vulnerability aligns with CWE-400, which categorizes memory allocation and deallocation issues as potential sources of denial of service conditions. From an ATT&CK framework perspective, this represents a system service denial of service technique that operates at the operating system level through library function manipulation. The attack vector requires physical proximity or direct storage device manipulation, making it a low-privilege but high-impact vulnerability in environments where storage device integrity cannot be fully guaranteed. Mitigation strategies should focus on upgrading to util-linux version 2.28 or later where the parsing logic has been corrected to properly validate partition table structures and implement appropriate bounds checking mechanisms. Additionally, system administrators should consider implementing storage device access controls and monitoring for anomalous partition table structures that may indicate exploitation attempts.