CVE-2020-8447Network attack vector

Authenticated service interruption via freed log buffer

Published Jan 30, 2020 · Updated Aug 4, 2024

Use-after-free in ossec-analysisd in OSSEC-HIDS 2.7 through 3.5.0 allows remote authenticated users to cause service interruption via syscheck messages. OS_ReadMSG cleans each message by storing hostname and program_name pointers into full_log, then the syscheck decoder frees full_log and replaces related pointers before later rule processing dereferences them. An authenticated remote agent must submit a valid syscheck-formatted message; the published analysis documents freed-heap access and possible process disruption but does not establish reliable code execution or data alteration.

CVSS severity9.8
Critical
EPSS probability1.94%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in ossec-analysisd in OSSEC-HIDS 2.7 through 3.5.0 allows remote authenticated users to cause service interruption via syscheck messages. OS_ReadMSG cleans each message by storing hostname and program_name pointers into full_log, then the syscheck decoder frees full_log and replaces related pointers before later rule processing dereferences them. An authenticated remote agent must submit a valid syscheck-formatted message; the published analysis documents freed-heap access and possible process disruption but does not establish reliable code execution or data alteration.

The record

CVE
CVE-2020-8447
Published
Jan 30, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 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

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NVDAV: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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1210Exploitation of Remote Services

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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