CVE-2020-15843

CVE-2020-15843 is a high-severity vulnerability in Actfax with a CVSS 3.x base score of 7.3. 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-276.

Key facts

Description

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 every user. Alternatively, the attacker can replace any of the binaries in the Client or Install directories. The latter requires additional user interaction, for example starting the client.

Frequently asked questions

What is CVE-2020-15843?
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 every user. Alternatively, the attacker can replace any of the binaries in the Client or Install directories. The latter requires additional user interaction, for example starting the client.
How severe is CVE-2020-15843?
CVE-2020-15843 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-15843 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-15843?
CVE-2020-15843 affects Actfax. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-15843?
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-2020-15843 published?
CVE-2020-15843 was published on 2020-09-24 and last updated on 2026-06-17.

References

Affected products (1)

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