CVE-2019-19449 : Exploit Details and Defense Strategies
Learn about CVE-2019-19449, a vulnerability in Linux kernel version 5.0.21 allowing slab-out-of-bounds read access in f2fs filesystem images. Find mitigation steps and prevention measures.
The f2fs filesystem image in the Linux kernel version 5.0.21 poses a risk of slab-out-of-bounds read access when mounted, specifically in the f2fs_build_segment_manager function within the segment.c file in the fs/f2fs directory. This issue is related to the init_min_max_mtime function also located in the segment.c file, where the second argument provided to the get_seg_entry function is not properly validated.
Understanding CVE-2019-19449
In the Linux kernel 5.0.21, mounting a crafted f2fs filesystem image can lead to slab-out-of-bounds read access in f2fs_build_segment_manager in fs/f2fs/segment.c, related to init_min_max_mtime in fs/f2fs/segment.c (because the second argument to get_seg_entry is not validated).
What is CVE-2019-19449?
This CVE refers to a vulnerability in the Linux kernel version 5.0.21 that allows for slab-out-of-bounds read access when mounting a specific f2fs filesystem image.
The Impact of CVE-2019-19449
The vulnerability can be exploited to gain unauthorized read access to sensitive kernel memory, potentially leading to information disclosure or further system compromise.
Technical Details of CVE-2019-19449
Vulnerability Description
The issue arises in the f2fs filesystem image in the Linux kernel version 5.0.21, specifically in the f2fs_build_segment_manager function within the segment.c file in the fs/f2fs directory.
Affected Systems and Versions
- Linux kernel version 5.0.21
Exploitation Mechanism
The vulnerability occurs due to improper validation of the second argument provided to the get_seg_entry function in the init_min_max_mtime function within the segment.c file.
Mitigation and Prevention
Immediate Steps to Take
- Apply patches provided by the Linux kernel maintainers to address the vulnerability.
- Avoid mounting untrusted or unknown f2fs filesystem images.
Long-Term Security Practices
- Regularly update the Linux kernel to the latest stable version to mitigate known vulnerabilities.
- Implement proper access controls and monitoring to detect unauthorized access attempts.
Patching and Updates
Ensure timely installation of security patches released by the Linux kernel development team to protect systems from potential exploitation.