CVE-2020-4887

Arbitrary file creation via gencore command

Published Jan 20, 2021 · Updated Sep 16, 2024

Arbitrary file creation in IBM AIX 7.1, 7.2 and VIOS 3.1 allows local users to create files in any directory via the gencore command. The gencore user command mishandles its file-creation operation, permitting attacker-controlled paths to receive new files. Exploitation requires local access; the reported consequence is filesystem integrity modification without reported confidentiality or availability impact.

CVSS severity6.2
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file creation in IBM AIX 7.1, 7.2 and VIOS 3.1 allows local users to create files in any directory via the gencore command. The gencore user command mishandles its file-creation operation, permitting attacker-controlled paths to receive new files. Exploitation requires local access; the reported consequence is filesystem integrity modification without reported confidentiality or availability impact.

The record

CVE
CVE-2020-4887
Published
Jan 20, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
AIX
Classifications
T1565
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=7.1
  2. Affected versionversion=7.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

IBM · AIXversion=7.1; version=7.2
IBM · PowerVM Virtual I/O Serverversion=3.1

Published CVSS scores

6.2IBM CorporationCVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
2.1NVDAV:L/AC:L/Au:N/C:N/I:P/A:N
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
5.4IBM CorporationCVSS:3.0/C:N/I:H/AC:L/AV:L/A:N/S:U/PR:N/UI:N/E:U/RL:O/RC: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1565Data Manipulation

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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