CVE-2018-3852: An exploitable denial of service vulnerability exists in the Ocularis Recorder functionality of Ocularis 5.5.0

This week

HIGH 7.5REMOTEDOWNGRADE

CVE-2018-3852 is a high-severity flaw (CVSS 7.5) affecting ocularis. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An exploitable denial of service vulnerability exists in the Ocularis Recorder functionality of Ocularis 5.5.0.242. A specially crafted TCP packet can cause a process to terminate resulting in denial of service. An attacker can send a crafted TCP packet to trigger this vulnerability.

Why this priority

High 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	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.8% (top 21%)
CISA exploited list	No
Weakness	CWE-20
Published	2018-06-06
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: onssi

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

Am I affected?

Timeline

2018-06-06 21:29 UTCPublished CVE record published
2026-06-17 01:57 UTCUpdated Record last modified

onssi ocularis DOWNGRADE

Affected: 5.5.0.242

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.5.0.242

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 5.5.0.242 (Debian / Ubuntu)

apt-cache madison ocularis sudo apt install ocularis=<VERSION_BEFORE_5.5.0.242> sudo apt-mark hold ocularis

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

dnf --showduplicates list ocularis sudo dnf downgrade ocularis-<VERSION_BEFORE_5.5.0.242> sudo dnf versionlock add ocularis

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-2018-3852?

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

Is CVE-2018-3852 being exploited?

CVE-2018-3852 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-2018-3852 affect?

CVE-2018-3852 affects ocularis. Severity is high (CVSS 7.5). An exploitable denial of service vulnerability exists in the Ocularis Recorder functionality of Ocularis 5.5.0.242. A specially crafted TCP packet can cause a process to terminate resulting in denial of service. An attacker can send a craft

How urgent is CVE-2018-3852?

Priority 56/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2020-27868 CRITICAL 9.8 DOWNGRADE This vulnerability allows remote attackers to execute arbitrary code on affected installations of Qognify Ocul

References

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