CVE-2020-5877Network attack vector

Service interruption via malformed iRules datagram input

Published Apr 30, 2020 · Updated Aug 4, 2024

Denial of service in affected F5 Networks BIG-IP releases allows remote attackers to interrupt service via malformed datagram input. The DATAGRAM::tcp iRules command processes malformed input when invoked from a FLOW_INIT event, but F5 has not disclosed the internal validation failure. Exposure requires an iRule that invokes this command in that event; the documented consequence is availability loss without data disclosure or modification.

CVSS severity7.5
High
EPSS probability1.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in affected F5 Networks BIG-IP releases allows remote attackers to interrupt service via malformed datagram input. The DATAGRAM::tcp iRules command processes malformed input when invoked from a FLOW_INIT event, but F5 has not disclosed the internal validation failure. Exposure requires an iRule that invokes this command in that event; the documented consequence is availability loss without data disclosure or modification.

The record

CVE
CVE-2020-5877
Published
Apr 30, 2020
Updated
Aug 4, 2024
Vendor
F5 Networks
Product
BIG-IP
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

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=15.0.0-15.1.0.1, 14.1.0-14.1.2.3, 13.1.0-13.1.3.3, 12.1.0-12.1.5.1, 11.6.1-11.6.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

F5 Networks · BIG-IPversion=15.0.0-15.1.0.1, 14.1.0-14.1.2.3, 13.1.0-13.1.3.3, 12.1.0-12.1.5.1, 11.6.1-11.6.5.1

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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