CVE-2020-7453

Kernel memory disclosure via unterminated jail osrelease

Published Apr 28, 2020 · Updated Aug 4, 2024

Kernel memory disclosure in FreeBSD 11.3 and 12.1 allows local users with jail superuser access to read host kernel memory. The jail_set system call accepts an osrelease string without verifying NUL termination, so jail_get returns bytes beyond the supplied value. Reachability requires superuser privileges in a jail configured with children.max above zero; default non-nested jails are unaffected.

CVSS severity6.0
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Kernel memory disclosure in FreeBSD 11.3 and 12.1 allows local users with jail superuser access to read host kernel memory. The jail_set system call accepts an osrelease string without verifying NUL termination, so jail_get returns bytes beyond the supplied value. Reachability requires superuser privileges in a jail configured with children.max above zero; default non-nested jails are unaffected.

The record

CVE
CVE-2020-7453
Published
Apr 28, 2020
Updated
Aug 4, 2024
Vendor
The FreeBSD Project
Product
FreeBSD
Classifications
CWE-754
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 28, 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

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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=12.1-STABLE before r359021, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r359020, 11.3-RELEASE before 11.3-RELEASE-p7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The FreeBSD Project · FreeBSDversion=12.1-STABLE before r359021, 12.1-RELEASE before 12.1-RELEASE-p3, 11.3-STABLE before r359020, 11.3-RELEASE before 11.3-RELEASE-p7

Published CVSS scores

6.0NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
3.3NIST NVDAV:L/AC:M/Au:N/C:P/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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions

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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