CVE-2018-6918 : Security Advisory and Response
Learn about CVE-2018-6918 affecting FreeBSD versions prior to 11.1-STABLE, leading to a denial of service issue. Find mitigation steps and prevention measures here.
In versions of FreeBSD prior to 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8, and 10.3-RELEASE-p28, a vulnerability exists in the ipsec option header, potentially leading to a denial of service attack.
Understanding CVE-2018-6918
This CVE describes a flaw in FreeBSD versions that could be exploited by a remote attacker to crash the system.
What is CVE-2018-6918?
The issue arises from an incorrect calculation of the ipsec option header's length field, causing an infinite loop when the length is zero, leading to a system crash.
The Impact of CVE-2018-6918
The vulnerability could be exploited by a remote attacker capable of sending a customized packet, resulting in a denial of service condition on the affected system.
Technical Details of CVE-2018-6918
This section provides more in-depth technical information about the CVE.
Vulnerability Description
The ipsec option header's length field does not include the size of the option header itself, leading to an infinite loop and system crash when the length is zero.
Affected Systems and Versions
- All supported versions of FreeBSD prior to 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8, and 10.3-RELEASE-p28.
Exploitation Mechanism
- A remote attacker can exploit this vulnerability by sending a customized packet, triggering the infinite loop and causing the system to crash.
Mitigation and Prevention
Protecting systems from CVE-2018-6918 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Apply the patches provided by FreeBSD to address the vulnerability.
- Monitor network traffic for any suspicious activity that could indicate an exploit attempt.
Long-Term Security Practices
- Regularly update and patch FreeBSD systems to prevent known vulnerabilities.
- Implement network segmentation and access controls to limit the impact of potential attacks.
Patching and Updates
- Ensure that all FreeBSD systems are updated to versions that include the fix for CVE-2018-6918 to mitigate the risk of exploitation.