CVE-2020-11766Network attack vector

Authenticated code execution via unsanitized fax form field

Published May 19, 2020 · Updated Aug 4, 2024

Command injection in AvantFAX before 3.3.6 and HylaFAX Enterprise Web Interface before 0.2.5 allows remote authenticated users to execute commands. The sendfax.php endpoint passes an unsanitized form field into command execution without neutralizing shell metacharacters. A valid web-interface account and network access are required; successful exploitation runs attacker-controlled commands with the web application's privileges.

CVSS severity8.8
High
EPSS probability1.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Command injection in AvantFAX before 3.3.6 and HylaFAX Enterprise Web Interface before 0.2.5 allows remote authenticated users to execute commands. The sendfax.php endpoint passes an unsanitized form field into command execution without neutralizing shell metacharacters. A valid web-interface account and network access are required; successful exploitation runs attacker-controlled commands with the web application's privileges.

The record

CVE
CVE-2020-11766
Published
May 19, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-78, T1059
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 19, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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