CVE-2021-20491

Name: CVE-2021-20491
Creator: NVD / NIST
Published: 2021-04-16T16:15:12.947+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.4/10EPSS 0.26%

Last modified Jun 17, 2026

CVE-2021-20491 is a medium-severity vulnerability rated 4.4/10 on the CVSS scale. IBM Spectrum Protect Server 7.1 and 8.1 is subject to a stack-based buffer overflow caused by improper bounds checking during the parsing of commands. By issuing such a command with an improper parameter, an authorized administrator could overflow a buffer and cause the server to crash. EPSS estimates a 0.26% chance of exploitation in the next 30 days.

Description

IBM Spectrum Protect Server 7.1 and 8.1 is subject to a stack-based buffer overflow caused by improper bounds checking during the parsing of commands. By issuing such a command with an improper parameter, an authorized administrator could overflow a buffer and cause the server to crash. IBM X-Force ID: 197792.

Metrics

CVSS 3.1

4.4/10

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.26%

17.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Ibm	Spectrum Protect	>= 7.1.0.000, < 7.1.13
Ibm	Spectrum Protect	>= 8.1.0.000, <= 8.1.10.100
Ibm	Spectrum Protect	8.1.11.000

References

https://exchange.xforce.ibmcloud.com/vulnerabilities/197792VDB Entry, Vendor Advisory
https://www.ibm.com/support/pages/node/6442993Patch, Vendor Advisory
https://exchange.xforce.ibmcloud.com/vulnerabilities/197792VDB Entry, Vendor Advisory
https://www.ibm.com/support/pages/node/6442993Patch, Vendor Advisory

Timeline

Published: Apr 16, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-20491?

How severe is CVE-2021-20491?

CVE-2021-20491 has a CVSS score of 4.4/10 (MEDIUM severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.

How do I fix CVE-2021-20491?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-20491?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST