CVE-2026-71402
Description
A flaw was found in wicked. An unauthenticated attacker on the same network who sends a crafted DHCP/UDP packet can trigger an out-of-bounds read vulnerability in the DHCPv4 option parser. This allows the client to parse adjacent heap memory as DHCP options, potentially leading to the disclosure of sensitive heap contents such as allocator metadata or pointer values into lease fields. The over-read is bounded to 68 bytes.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Mitigation
Systems configured with static IP addresses that do not rely on DHCP for network configuration can disable the `wickedd-dhcp4` service. This prevents the system from processing DHCPv4 packets and eliminates the vulnerability.
To disable the service:
`sudo systemctl disable --now wickedd-dhcp4.service`
Note that disabling this service will prevent the system from obtaining an IP address via DHCP.
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. This can often be used to subvert any other security service.
Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
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