CVE-2017-8779 : Exploit Details and Defense Strategies

This CVE-2017-8779 article provides insights into a vulnerability in rpcbind, LIBTIRPC, and NTIRPC versions, allowing attackers to execute a denial of service attack through memory consumption.

Understanding CVE-2017-8779

What is CVE-2017-8779?

The memory allocation process in rpcbind, LIBTIRPC, and NTIRPC versions does not consider the maximum size of RPC data for XDR strings, enabling attackers to trigger a denial of service attack by sending a manipulated UDP packet to port 111.

The Impact of CVE-2017-8779

This vulnerability, also known as rpcbomb, allows attackers to consume memory without freeing it, leading to a denial of service condition.

Technical Details of CVE-2017-8779

Vulnerability Description

The vulnerability in rpcbind, LIBTIRPC, and NTIRPC versions allows remote attackers to cause a denial of service by crafting UDP packets to exploit memory allocation issues.

Affected Systems and Versions

rpcbind versions up to 0.2.4
LIBTIRPC versions up to 1.0.1 and 1.0.2-rc through 1.0.2-rc3
NTIRPC versions up to 1.4.3

Exploitation Mechanism

Attackers exploit this vulnerability by sending manipulated UDP packets to port 111, causing memory consumption without proper release.

Mitigation and Prevention

Immediate Steps to Take

Apply patches provided by the respective vendors promptly
Implement network-level controls to filter potentially malicious UDP packets

Long-Term Security Practices

Regularly update and patch all software components
Conduct security assessments to identify and mitigate similar vulnerabilities

Patching and Updates

Refer to vendor advisories for specific patching instructions and updates