CVE-2021-20490

Local service interruption via missing directory sticky bits

Published Jun 29, 2021 · Updated Sep 16, 2024

Incorrect permissions in IBM Spectrum Protect Plus 10.1.0 through 10.1.8 allow local users to interrupt service through shared directories. Several world-writable directories lack the sticky bit, so they do not restrict removal or renaming of entries to each entry's owner. Local access to the Linux-based appliance is required, and successful exploitation interrupts the service without reported confidentiality or integrity impact.

CVSS severity4.0
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect permissions in IBM Spectrum Protect Plus 10.1.0 through 10.1.8 allow local users to interrupt service through shared directories. Several world-writable directories lack the sticky bit, so they do not restrict removal or renaming of entries to each entry's owner. Local access to the Linux-based appliance is required, and successful exploitation interrupts the service without reported confidentiality or integrity impact.

The record

CVE
CVE-2021-20490
Published
Jun 29, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM Spectrum Protect Plus
Classifications
CWE-276, T1489
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 29, 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=10.1.0
  2. Affected versionversion=10.1.8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

IBM · IBM Spectrum Protect Plusversion=10.1.0; version=10.1.8

Published CVSS scores

3.5IBM CorporationCVSS:3.0/I:N/AC:L/S:U/C:N/AV:L/UI:N/PR:N/A:L/RL:O/E:U/RC:C
4.0IBM CorporationCVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
2.1NIST NVDAV:L/AC:L/Au:N/C:N/I:N/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.

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

CWE-276Incorrect Default Permissions
T1489Service Stop

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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