CVE-2022-0435: Linux Kernel TIPC Buffer Overflow Flaw

CVE-2022-0435 Overview

A stack overflow flaw was found in the Linux kernel's TIPC (Transparent Inter-Process Communication) protocol functionality. The vulnerability occurs when a user sends a packet with malicious content where the number of domain member nodes exceeds the 64 allowed limit. This flaw allows a remote user to crash the system or possibly escalate their privileges if they have access to the TIPC network.

Critical Impact

Remote attackers with TIPC network access can trigger a stack overflow leading to system crash or potential privilege escalation, affecting a wide range of Linux distributions and enterprise systems.

Affected Products

• Linux Kernel (multiple versions up to 5.17-rc3)
• Red Hat Enterprise Linux 8.x (including EUS, TUS, and AUS variants)
• Red Hat CodeReady Linux Builder 8.x
• Red Hat Virtualization 4.0 and Virtualization Host 4.0
• Fedora 34 and 35
• oVirt Node 4.4.10
• NetApp H-Series Firmware (H300E, H300S, H410S, H500E, H500S, H700E, H700S)

Discovery Timeline

• 2022-03-25 - CVE-2022-0435 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-0435

Vulnerability Analysis

This vulnerability exists in the TIPC protocol implementation within the Linux kernel. TIPC is a cluster-oriented networking protocol designed for efficient communication between nodes in a cluster. The flaw is classified as CWE-787 (Out-of-bounds Write), which manifests as a stack overflow condition.

The vulnerability occurs during the processing of TIPC domain membership updates. When the kernel receives a TIPC packet containing domain member node information, it fails to properly validate the count of member nodes before copying the data to a stack buffer. Since the protocol allows a maximum of 64 domain member nodes, an attacker can craft a packet claiming more than 64 nodes, causing data to be written beyond the allocated stack buffer boundaries.

Successful exploitation requires network access to the TIPC protocol. While TIPC is not enabled by default in most Linux distributions, systems configured for cluster communication using TIPC are at risk. The network-based attack vector combined with the potential for kernel-level code execution makes this vulnerability particularly concerning for clustered environments and data centers.

Root Cause

The root cause of this vulnerability is insufficient bounds checking in the TIPC protocol handler when processing domain member node counts. The kernel code accepts the attacker-supplied count without validating it against the maximum allowed value of 64 nodes, leading to a stack buffer overflow when the excessive data is copied.

The missing validation allows an attacker to overflow the stack-allocated buffer, potentially overwriting return addresses, saved registers, or other critical stack data. This type of memory corruption in kernel space can lead to system instability or enable arbitrary code execution with kernel privileges.

Attack Vector

The attack is performed over the network, requiring the attacker to have access to the TIPC network infrastructure. The attacker crafts a malicious TIPC packet that contains a domain member node count exceeding the 64-node limit. When this packet is processed by a vulnerable kernel, the overflow occurs in kernel space.

The attack does not require user interaction, making it suitable for automated exploitation. However, the attacker must be positioned within the TIPC network topology to send packets that will be processed by the target system. The exploitation can result in a denial of service through kernel crash or, in more sophisticated scenarios, privilege escalation to kernel-level access.

Detection Methods for CVE-2022-0435

Indicators of Compromise

• Unexpected kernel panics or system crashes related to TIPC network processing
• Anomalous TIPC traffic patterns showing packets with unusually high member node counts (exceeding 64)
• Stack traces in kernel logs referencing TIPC protocol handling functions
• Evidence of TIPC module loading on systems where it is not expected

Detection Strategies

• Monitor kernel logs for stack overflow errors or panics originating from TIPC-related kernel functions
• Implement network monitoring to detect TIPC packets with malformed or excessive domain member counts
• Deploy intrusion detection rules that flag TIPC traffic anomalies, particularly packets attempting to specify more than 64 domain member nodes
• Use kernel live patching detection mechanisms to verify TIPC module integrity

Monitoring Recommendations

• Configure SIEM rules to alert on repeated kernel crashes or TIPC-related error messages
• Monitor network traffic on TIPC ports for unusual packet sizes or frequencies
• Implement audit logging for TIPC module loading and unloading events
• Review system integrity monitoring for unexpected modifications to kernel modules

How to Mitigate CVE-2022-0435

Immediate Actions Required

• Apply security patches from your Linux distribution vendor immediately
• If TIPC is not required, disable or blacklist the TIPC kernel module (tipc.ko) to eliminate the attack surface
• Restrict network access to TIPC ports using firewall rules to limit exposure
• Consider enabling kernel address space layout randomization (KASLR) as an additional defense layer

Patch Information

Security patches are available from multiple vendors. For detailed patch information, consult the Red Hat Bug Report #2048738 which tracks this vulnerability. NetApp has also released advisories for affected firmware; see the NetApp Security Advisory NTAP-20220602-0001 for H-Series devices. The vulnerability was publicly discussed on the OpenWall OSS Security mailing list.

Update your Linux kernel to a patched version appropriate for your distribution. For Red Hat Enterprise Linux 8.x systems, apply the corresponding security updates. Fedora 34 and 35 users should update through the standard package management system.

Workarounds

• Blacklist the TIPC kernel module by adding blacklist tipc to /etc/modprobe.d/blacklist.conf if TIPC functionality is not required
• Implement network segmentation to restrict TIPC traffic to trusted network segments only
• Apply firewall rules to drop incoming TIPC packets from untrusted sources
• Use Security-Enhanced Linux (SELinux) or AppArmor policies to restrict TIPC module loading

# Disable TIPC kernel module
echo "blacklist tipc" >> /etc/modprobe.d/blacklist.conf
echo "install tipc /bin/false" >> /etc/modprobe.d/blacklist.conf

# Unload TIPC module if currently loaded
rmmod tipc 2>/dev/null || true

# Verify TIPC module is not loaded
lsmod | grep tipc