CVE-2019-9747 : Vulnerability Insights and Analysis
Discover the impact of CVE-2019-9747, a vulnerability in tinysvcmdns allowing a denial-of-service attack through an infinite loop triggered by a malicious mDNS packet. Learn mitigation steps and long-term security practices.
This CVE-2019-9747 article provides insights into a vulnerability in tinysvcmdns that allows for a denial-of-service attack due to an infinite loop triggered by a maliciously crafted mDNS packet.
Understanding CVE-2019-9747
What is CVE-2019-9747?
In tinysvcmdns until 2018-01-16, a flaw allows a specially crafted mDNS packet to cause an infinite loop during the parsing of an mDNS query, leading to a denial-of-service condition.
The Impact of CVE-2019-9747
The vulnerability results in the mDNS server becoming unresponsive when processing the malicious mDNS packet, potentially disrupting network services.
Technical Details of CVE-2019-9747
Vulnerability Description
- Maliciously crafted mDNS packet triggers an infinite loop in parsing mDNS queries
- Function uncompress_nlabel enters an endless loop when analyzing the packet
Affected Systems and Versions
- Affected version: tinysvcmdns until 2018-01-16
Exploitation Mechanism
- Exploiting interconnected mDNS compressed labels to trigger the infinite loop
Mitigation and Prevention
Immediate Steps to Take
- Avoid using tinysvcmdns for new projects or products
- Consider alternative mDNS libraries with active maintenance
Long-Term Security Practices
- Regularly monitor for security updates and patches
- Conduct thorough security assessments of third-party libraries before integration
Patching and Updates
- As the tinysvcmdns project is abandoned and known to have vulnerabilities, it is recommended to cease its usage and migrate to supported alternatives.