CVE-2021-3375: ActivePresenter 6.1.6 is affected by a memory corruption vulnerability that may result in a denial of service

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2021-3375 is a critical-severity flaw (CVSS 9.8) affecting activepresenter. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

ActivePresenter 6.1.6 is affected by a memory corruption vulnerability that may result in a denial of service (DoS) or arbitrary code execution.

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	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	3.5% (top 11%)
CISA exploited list	No
Weakness	CWE-787
Published	2021-02-15
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: atomisystems

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

Am I affected?

Timeline

2021-02-15 18:15 UTCPublished CVE record published
2026-06-17 04:04 UTCUpdated Record last modified

atomisystems activepresenter DOWNGRADE

Affected: 6.1.6

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.1.6

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 6.1.6 (Debian / Ubuntu)

apt-cache madison activepresenter sudo apt install activepresenter=<VERSION_BEFORE_6.1.6> sudo apt-mark hold activepresenter

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

dnf --showduplicates list activepresenter sudo dnf downgrade activepresenter-<VERSION_BEFORE_6.1.6> sudo dnf versionlock add activepresenter

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-2021-3375?

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

Is CVE-2021-3375 being exploited?

CVE-2021-3375 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-2021-3375 affect?

CVE-2021-3375 affects activepresenter. Severity is critical (CVSS 9.8). ActivePresenter 6.1.6 is affected by a memory corruption vulnerability that may result in a denial of service (DoS) or arbitrary code execution.

How urgent is CVE-2021-3375?

Priority 67/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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