Linux Kernel hfsplus_lookup() Function NULL Pointer Dereference Vulnerability [CVE-2018-14617]

CVE number – CVE-2018-14617

A vulnerability in the hfsplus_lookup() function of the Linux Kernel could allow a local attacker to cause a denial of service (DoS) condition on a targeted system.

The vulnerability occurs when the hfsplus_lookup() function, as defined in the fs/hfsplus/dir.c source code file of the affected software, opens a file in a read-only Hierarchical File System Plus (HFS+) filesystem without a metadata directory and with malformed catalog data. An attacker could exploit this vulnerability by mounting a malicious HFS+ filesystem image and opening a file in the image, triggering a NULL pointer dereference condition and a kernel panic. A successful exploit could cause a DoS condition.

Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available.

Kernel.org has confirmed the vulnerability; however, software updates are not available.

Analysis
  • To exploit this vulnerability, the attacker must have user-level access to the targeted system. This access requirement may reduce the likelihood of a successful exploit.

    At the time this alert was first published, a suggested patch was available in the Linux Kernel Mailing List (LKML) archive. However, the patch had not been pushed upstream to Kernel.org.

Safeguards
  • Administrators are advised to contact the vendor regarding future updates and releases.

    Administrators are advised to allow only trusted users to access local systems.

    Administrators are advised to allow only privileged users to access administration or management systems.

    Administrators are advised to monitor critical systems.

Fixed Software
  • At the time this alert was first published, Kernel.org had not released a software patch.





Duncan Newell

Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.

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