How severe is CVE-2019-9747?

CVE-2019-9747 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2019-9747 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-9747?

CVE-2019-9747 affects Tinysvcmdns Project Tinysvcmdns. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-9747?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-9747 published?

CVE-2019-9747 was published on 2019-03-13 and last updated on 2026-06-17.

CVE-2019-9747

CVE-2019-9747 is a high-severity vulnerability in Tinysvcmdns Project Tinysvcmdns with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-835.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-835
Affected product: Tinysvcmdns Project Tinysvcmdns
Published: 2019-03-13
Last modified: 2026-06-17

Description

In tinysvcmdns through 2018-01-16, a maliciously crafted mDNS (Multicast DNS) packet triggers an infinite loop while parsing an mDNS query. When mDNS compressed labels point to each other, the function uncompress_nlabel goes into an infinite loop trying to analyze the packet with an mDNS query. As a result, the mDNS server hangs after receiving the malicious mDNS packet. NOTE: the product's web site states "This project is un-maintained, and has been since 2013. ... There are known vulnerabilities ... You are advised to NOT use this library for any new projects / products."

Frequently asked questions

What is CVE-2019-9747?: In tinysvcmdns through 2018-01-16, a maliciously crafted mDNS (Multicast DNS) packet triggers an infinite loop while parsing an mDNS query. When mDNS compressed labels point to each other, the function uncompress_nlabel goes into an infinite loop trying to analyze the packet with an mDNS query. As a result, the mDNS server hangs after receiving the malicious mDNS packet. NOTE: the product's web site states "This project is un-maintained, and has been since 2013. ... There are known vulnerabilities ... You are advised to NOT use this library for any new projects / products."
How severe is CVE-2019-9747?: CVE-2019-9747 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2019-9747 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-9747?: CVE-2019-9747 affects Tinysvcmdns Project Tinysvcmdns. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-9747?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-9747 published?: CVE-2019-9747 was published on 2019-03-13 and last updated on 2026-06-17.

References

https://bitbucket.org/geekman/tinysvcmdns/issues/11/denial-of-service-vulnerability-infinite

Affected products (1)

cpe:2.3:a:tinysvcmdns_project:tinysvcmdns:*:*:*:*:*:*:*:*

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