CVE-2021-20076Network attack vector

Authenticated code execution via PHP unserialization

Published Mar 3, 2021 · Updated Aug 3, 2024

PHP object injection in Tenable Security Center 5.13.0 through 5.17.0 allows remote authenticated users to execute code on the server. The server unserializes PHP data supplied through an authenticated request, enabling crafted objects to trigger code execution; the affected endpoint and call site are undisclosed. An unprivileged product account is sufficient, and successful exploitation runs code in the server application's context.

CVSS severity9.0
Critical
EPSS probability1.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

PHP object injection in Tenable Security Center 5.13.0 through 5.17.0 allows remote authenticated users to execute code on the server. The server unserializes PHP data supplied through an authenticated request, enabling crafted objects to trigger code execution; the affected endpoint and call site are undisclosed. An unprivileged product account is sufficient, and successful exploitation runs code in the server application's context.

The record

CVE
CVE-2021-20076
Published
Mar 3, 2021
Updated
Aug 3, 2024
Vendor
Tenable
Product
Tenable Security Center
Classifications
CWE-502, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 3, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.13.0 through 5.17.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Tenable · Tenable Security Centerversion=5.13.0 through 5.17.0

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
9.0TenableAV:N/AC:L/Au:S/C:C/I:C/A:C
7.0TenableAV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:OF/RC:C

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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