CVE-2020-7454Network attack vector

Kernel memory read or write via malformed packets

Published May 13, 2020 · Updated Aug 4, 2024

Out-of-bounds access in FreeBSD libalias allows remote attackers to read or write kernel or natd memory via crafted packets. Protocol handlers access headers without first ensuring that the supplied packet contains those headers, causing out-of-bounds reads or writes. Exposure requires ipfw and NAT together; affected packets can disclose or corrupt kernel memory with in-kernel NAT or process memory with natd.

CVSS severity9.8
Critical
EPSS probability2.71%
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

Out-of-bounds access in FreeBSD libalias allows remote attackers to read or write kernel or natd memory via crafted packets. Protocol handlers access headers without first ensuring that the supplied packet contains those headers, causing out-of-bounds reads or writes. Exposure requires ipfw and NAT together; affected packets can disclose or corrupt kernel memory with in-kernel NAT or process memory with natd.

The record

CVE
CVE-2020-7454
Published
May 13, 2020
Updated
Aug 4, 2024
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
CWE-787, CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 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=FreeBSD 12.1-RELEASE before p5, 11.4-BETA1 before p1, and 11.3-RELEASE before p9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The FreeBSD Project · FreeBSDversion=FreeBSD 12.1-RELEASE before p5, 11.4-BETA1 before p1, and 11.3-RELEASE before p9

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-20Improper Input Validation
T1499.004Application or System Exploitation

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