CVE-2024-0607 Overview
A buffer corruption vulnerability has been discovered in the Linux kernel's Netfilter subsystem. The flaw exists in the nft_byteorder_eval() function, where improper memory handling during loop iterations causes data corruption. On each iteration, 8 bytes are written to the dst array, but since dst is defined as an array of u32 (32-bit unsigned integers), each element only has space for 4 bytes. This mismatch results in each iteration overwriting part of the previous element, corrupting the array contents.
Critical Impact
A local user can exploit this vulnerability to cause a denial of service condition or potentially break NetFilter functionality, affecting network filtering capabilities on affected Linux systems.
Affected Products
- Linux Kernel (including version 6.7-rc1)
- Fedora 39
- Red Hat Enterprise Linux 8.0 and 9.0
Discovery Timeline
- January 18, 2024 - CVE-2024-0607 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2024-0607
Vulnerability Analysis
The vulnerability resides in the Netfilter subsystem's byte order conversion functionality within the Linux kernel. The nft_byteorder_eval() function is responsible for handling byte order transformations for network filter expressions. The function contains a fundamental programming error where the size of write operations exceeds the allocated space for destination array elements.
The root issue is a type mismatch: the code writes 8-byte values during each iteration, but the destination buffer dst is declared as an array of u32 types, which only accommodate 4 bytes each. This causes each subsequent write to corrupt the previously written value, leading to unpredictable behavior in the Netfilter subsystem.
Exploitation requires local access to the system, making this a local attack vector. While the vulnerability does not appear to allow arbitrary code execution, it can reliably cause denial of service by corrupting Netfilter's internal data structures. Additionally, the corruption could potentially disable or bypass network filtering rules, creating security gaps in firewall configurations.
Root Cause
The root cause is an Out-of-Bounds Write vulnerability (CWE-229) in the nft_byteorder_eval() function. The code incorrectly assumes that the destination array can accommodate 8-byte writes per element, when in reality each u32 element can only store 4 bytes. This buffer size miscalculation leads to memory corruption on every loop iteration after the first.
Attack Vector
This vulnerability requires local access to exploit. An attacker with local user privileges on an affected Linux system can trigger the vulnerable code path through the Netfilter subsystem interface. The attack does not require user interaction and can be executed with low privileges.
The attacker would need to craft specific Netfilter expressions that invoke the nft_byteorder_eval() function in a manner that triggers the buffer corruption. This could be accomplished through the nft (nftables) command-line utility or via direct netlink socket communications to the kernel's Netfilter subsystem.
Detection Methods for CVE-2024-0607
Indicators of Compromise
- Unexpected kernel crashes or panics with stack traces referencing nft_byteorder_eval or Netfilter components
- System logs showing Netfilter-related errors or memory corruption warnings in dmesg output
- Unexplained changes in network filtering behavior or firewall rules not functioning as expected
- Repeated system instability when network filtering operations are performed
Detection Strategies
- Monitor kernel logs for oops messages or stack traces involving the Netfilter subsystem
- Implement host-based intrusion detection to flag unusual nftables or iptables operations by unprivileged users
- Use kernel auditing to track calls to Netfilter-related syscalls from non-administrative accounts
- Deploy endpoint detection solutions capable of monitoring kernel-level anomalies
Monitoring Recommendations
- Enable kernel crash dump collection to capture evidence if the vulnerability is exploited
- Configure syslog aggregation to centralize kernel messages for correlation analysis
- Set up alerting for repeated Netfilter errors that could indicate exploitation attempts
- Review system audit logs for suspicious user activity involving network filter manipulation
How to Mitigate CVE-2024-0607
Immediate Actions Required
- Update affected Linux kernel versions to the latest patched releases from your distribution
- Review and restrict local user access on critical systems until patches are applied
- Monitor Netfilter functionality to detect any anomalies indicating potential exploitation
- Consider temporarily restricting access to nftables interfaces for non-administrative users
Patch Information
The vulnerability has been addressed in the upstream Linux kernel. The fix is available in commit c301f0981fdd3fd1ffac6836b423c4d7a8e0eb63 in the Linux kernel Git repository. Major distributions including Red Hat, Fedora, and Debian have released patched kernel packages. Consult your distribution's security advisories for specific package versions:
Workarounds
- Limit local user access on affected systems to trusted administrators only
- Restrict access to Netfilter/nftables configuration interfaces using system permissions
- Implement network segmentation to contain potential impact if Netfilter functionality is compromised
- Consider deploying additional network filtering at the perimeter to compensate for any local Netfilter disruption
# Check current kernel version for vulnerability status
uname -r
# For Red Hat/CentOS systems, check if patched kernel is available
yum check-update kernel
# For Debian/Ubuntu systems
apt list --upgradable | grep linux-image
# Apply kernel updates on Red Hat/CentOS
yum update kernel
# Apply kernel updates on Debian/Ubuntu
apt update && apt upgrade linux-image-*
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
