Linux · Linux Kernel · CVE-2009-4272
**Name of the Vulnerable Software and Affected Versions**
Linux kernel version 2.6.18 on Red Hat Enterprise Linux (RHEL) 5
**Description**
The issue allows remote attackers to cause a denial of service (deadlock) via crafted packets that force collisions in the IPv4 routing hash table, triggering a routing "emergency" in which a hash chain is too long. This is related to an issue in the Linux kernel before 2.6.31, involving an uninitialized pointer and a panic when the kernel routing cache is disabled.
**Recommendations**
For Linux kernel version 2.6.18 on Red Hat Enterprise Linux (RHEL) 5, consider applying the Red Hat patch to resolve the issue. As a temporary workaround, restrict access to the network to minimize the risk of exploitation.