CVE-2020-15843: ActFax Version 7.10 Build 0335 (2020-05-25) is susceptible to a privilege escalation vulnerability due to inse

Routine

HIGH 7.3DOWNGRADE

CVE-2020-15843 is a high-severity flaw (CVSS 7.3) affecting actfax. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

ActFax Version 7.10 Build 0335 (2020-05-25) is susceptible to a privilege escalation vulnerability due to insecure folder permissions on %PROGRAMFILES%\ActiveFax\Client\, %PROGRAMFILES%\ActiveFax\Install\ and %PROGRAMFILES%\ActiveFax\Terminal\. The folder permissions allow "Full Control" to "Everyone". An authenticated local attacker can exploit this to replace the TSClientB.exe binary in the Terminal directory, which is executed on logon for eve

Why this priority

High severity
Public exploit reference

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

Risk facts

CVSS score	7.3 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.4% (top 66%)
CISA exploited list	No
Weakness	CWE-276
Published	2020-09-24
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: actfax

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

Am I affected?

Timeline

2020-09-24 23:15 UTCPublished CVE record published
2026-06-17 02:57 UTCUpdated Record last modified

actfax actfax DOWNGRADE

Affected: 7.10 build_0335

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.10

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 7.10 (Debian / Ubuntu)

apt-cache madison actfax sudo apt install actfax=<VERSION_BEFORE_7.10> sudo apt-mark hold actfax

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

dnf --showduplicates list actfax sudo dnf downgrade actfax-<VERSION_BEFORE_7.10> sudo dnf versionlock add actfax

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-2020-15843?

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

Is CVE-2020-15843 being exploited?

CVE-2020-15843 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-2020-15843 affect?

CVE-2020-15843 affects actfax. Severity is high (CVSS 7.3). ActFax Version 7.10 Build 0335 (2020-05-25) is susceptible to a privilege escalation vulnerability due to insecure folder permissions on %PROGRAMFILES%\ActiveFax\Client\, %PROGRAMFILES%\ActiveFax\Install\ and %PROGRAMFILES%\ActiveFax\Termin

How urgent is CVE-2020-15843?

Priority 39/100. High severity; Public exploit reference

References

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