CVE-2020-25581Network attack vector

Jailed-process survival via jail_remove race

Published Mar 26, 2021 · Updated Aug 4, 2024

A race condition in FreeBSD 12.2-STABLE before r369312 and 11.4-STABLE before r369313 allows remote authenticated users to leave jailed processes running. The jail_remove(2) implementation can miss processes during concurrent jail teardown, so some processes survive removal instead of being killed. The operation requires authenticated access capable of invoking jail management and can undermine isolation or service-termination expectations without proving broader host compromise.

CVSS severity7.5
High
EPSS probability0.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A race condition in FreeBSD 12.2-STABLE before r369312 and 11.4-STABLE before r369313 allows remote authenticated users to leave jailed processes running. The jail_remove(2) implementation can miss processes during concurrent jail teardown, so some processes survive removal instead of being killed. The operation requires authenticated access capable of invoking jail management and can undermine isolation or service-termination expectations without proving broader host compromise.

The record

CVE
CVE-2020-25581
Published
Mar 26, 2021
Updated
Aug 4, 2024
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
CWE-362
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 26, 2021CVE 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

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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=FreeBSD 12.2-RELEASE before p4, 11.4-RELEASE before p8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The FreeBSD Project · FreeBSDversion=FreeBSD 12.2-RELEASE before p4, 11.4-RELEASE before p8

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
8.5NVDAV:N/AC:M/Au:S/C:C/I:C/A: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 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-362Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition)

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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