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Public proof of concept

CVE-2020-7461

A public proof of concept exists; no exploitation attested.

  • Published2021-03-26
  • WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

In FreeBSD 12.1-STABLE before r365010, 11.4-STABLE before r365011, 12.1-RELEASE before p9, 11.4-RELEASE before p3, and 11.3-RELEASE before p13, dhclient(8) fails to handle certain malformed input related to handling of DHCP option 119 resulting a heap overflow. The heap overflow could in principle be exploited to achieve remote code execution. The affected process runs with reduced privileges in a Capsicum sandbox, limiting the immediate impact of an exploit.

Timeline

dates in UTC
  1. 2021-03-2621:15CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-7461?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-7461?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Freebsd
BranchAffectedFixed in
11.3= 11.3no fix published
11.4= 11.4no fix published
12.1= 12.1no fix published
Siemens simatic rf350m firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published
Siemens simatic rf650m firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • ICSA-21-257-11 CISA2 known affected

    Siemens SIMATIC RFID

    SIMATIC RF350M · SIMATIC RF650M

Full record on NVD

Fix

  1. Workaround from the vendor CISA ICSA-21-257-11 · 2 productsProtect network access to affected devices.
  2. Mitigation from the vendor CISA ICSA-21-257-11 · 2 productsUse trusted DNS servers in internal network, and restrict DNS traffic to this network only through firewalls.
  3. No fix available, says the vendor CISA ICSA-21-257-11 · 2 productsCurrently no remediation is available

Advisories and patches

Detection

read 2026-10-23 19:23 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
2 repositories, unverifiedknqyf263/CVE-2020-74610xkol/freebsd-dhclient-poc
PoC-in-GitHub

Sources

  • NVDCVSS 3.17.3read 2026-10-23
  • NVDCVSS 2.07.5read 2026-10-23
  • NVDweakness (CWE)CWE-787read 2026-10-23
  • FIRST EPSSEPSS score4.1 %2026-10-22
  • PoC-in-GitHubproof of concept2read 2026-10-23

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Published
2021-03-26
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2020-7461?

In FreeBSD 12.1-STABLE before r365010, 11.4-STABLE before r365011, 12.1-RELEASE before p9, 11.4-RELEASE before p3, and 11.3-RELEASE before p13, dhclient(8) fails to handle certain malformed input related to handling of DHCP option 119 resulting a heap overflow. The heap overflow could in principle be exploited to achieve remote code execution. The affected process runs with reduced privileges in a Capsicum sandbox, limiting the immediate impact of an exploit.

Is CVE-2020-7461 actively exploited?

Active exploitation of CVE-2020-7461 has not been confirmed. Its EPSS score was 4.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-7461?

CVE-2020-7461 has a CVSS v3 base score of 7.3 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

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