CVE-2020-5889Network attack vector

Reflected XSS via incorrect portal base URL

Published Apr 30, 2020 · Updated Aug 4, 2024

Reflected XSS in affected F5 BIG-IP Access Policy Manager releases allows remote authenticated users to execute script in a victim's browser. The Portal Access response rewriter derives an incorrect base URL from a crafted HTTP request and emits attacker-controlled content into the rewritten backend response without safe neutralization. Exploitation requires authenticated portal access, a configured untrusted backend, and user interaction; successful script execution can read or alter data available to the victim's browser session.

CVSS severity5.4
Medium
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Reflected XSS in affected F5 BIG-IP Access Policy Manager releases allows remote authenticated users to execute script in a victim's browser. The Portal Access response rewriter derives an incorrect base URL from a crafted HTTP request and emits attacker-controlled content into the rewritten backend response without safe neutralization. Exploitation requires authenticated portal access, a configured untrusted backend, and user interaction; successful script execution can read or alter data available to the victim's browser session.

The record

CVE
CVE-2020-5889
Published
Apr 30, 2020
Updated
Aug 4, 2024
Vendor
F5 Networks
Product
BIG-IP Access Policy Manager
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 30, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=15.1.0-15.1.0.1, 15.0.0-15.0.1.2, 14.1.0-14.1.2.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

F5 Networks · BIG-IP Access Policy Managerversion=15.1.0-15.1.0.1, 15.0.0-15.0.1.2, 14.1.0-14.1.2.3

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo