CVE-2017-12087: An exploitable heap overflow vulnerability exists in the tinysvcmdns library version 2016-07-18

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CRITICAL 10.0REMOTEDOWNGRADE

CVE-2017-12087 is a critical-severity flaw (CVSS 10.0) affecting tinysvcmdns. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An exploitable heap overflow vulnerability exists in the tinysvcmdns library version 2016-07-18. A specially crafted packet can make the library overwrite an arbitrary amount of data on the heap with attacker controlled values. An attacker needs send a dns packet to trigger this vulnerability.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	10.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.0% (top 19%)
CISA exploited list	No
Weakness	CWE-119
Published	2018-04-24
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: tinysvcmdns project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-04-24 19:29 UTCPublished CVE record published
2026-06-17 01:02 UTCUpdated Record last modified

tinysvcmdns project tinysvcmdns DOWNGRADE

Affected: 2016-07-18

Fixed in: no fixed release known

Safe to downgrade to: a release before 2016-07-18

1. Check installed version

apt-cache policy tinysvcmdns || rpm -q tinysvcmdns || tinysvcmdns --version

2. No fixed release: DOWNGRADE to a release before 2016-07-18 (Debian / Ubuntu)

apt-cache madison tinysvcmdns sudo apt install tinysvcmdns=<VERSION_BEFORE_2016-07-18> sudo apt-mark hold tinysvcmdns

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list tinysvcmdns sudo dnf downgrade tinysvcmdns-<VERSION_BEFORE_2016-07-18> sudo dnf versionlock add tinysvcmdns

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2017-12087?

tinysvcmdns: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2017-12087 being exploited?

CVE-2017-12087 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2017-12087 affect?

CVE-2017-12087 affects tinysvcmdns. Severity is critical (CVSS 10.0). An exploitable heap overflow vulnerability exists in the tinysvcmdns library version 2016-07-18. A specially crafted packet can make the library overwrite an arbitrary amount of data on the heap with attacker controlled values. An attacker

How urgent is CVE-2017-12087?

Priority 65/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2019-9748 CRITICAL 9.1 UPGRADE In tinysvcmdns through 2018-01-16, an mDNS server processing a crafted packet can perform arbitrary data read
CVE-2019-9747 HIGH 7.5 UPGRADE In tinysvcmdns through 2018-01-16, a maliciously crafted mDNS (Multicast DNS) packet triggers an infinite loop
CVE-2017-12130 HIGH 7.5 DOWNGRADE An exploitable NULL pointer dereference vulnerability exists in the tinysvcmdns library version 2017-11-05

References

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