CVE-2018-5391

Published: 14 August 2018

The Linux kernel, versions 3.9+, is vulnerable to a denial of service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial of service condition by sending specially crafted IP fragments. Various vulnerabilities in IP fragmentation have been discovered and fixed over the years. The current vulnerability (CVE-2018-5391) became exploitable in the Linux kernel with the increase of the IP fragment reassembly queue size.

From the Ubuntu Security Team

Juha-Matti Tilli discovered that the IP implementation in the Linux kernel performed algorithmically expensive operations in some situations when handling incoming packet fragments. A remote attacker could use this to cause a denial of service.

Notes

CERT recommends reverting c2a936600f78aea00d3312ea4b66a79a4619f9b4

Status

Severity score breakdown

References

• https://www.kb.cert.org/vuls/id/641765
• https://ubuntu.com/security/notices/USN-3740-1
• https://ubuntu.com/security/notices/USN-3740-2
• https://ubuntu.com/security/notices/USN-3741-1
• https://ubuntu.com/security/notices/USN-3741-2
• https://ubuntu.com/security/notices/USN-3742-1
• https://ubuntu.com/security/notices/USN-3742-2
• https://www.cve.org/CVERecord?id=CVE-2018-5391
• NVD
• Launchpad
• Debian