CVE-2021-28940

Name: CVE-2021-28940
Creator: NVD / NIST
Published: 2021-04-02T20:15:13.317+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 3.30%

Last modified Jun 17, 2026

CVE-2021-28940 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Because of a incorrect escaped exec command in MagpieRSS in 0.72 in the /extlib/Snoopy.class.inc file, it is possible to add a extra command to the curl binary. This creates an issue on the /scripts/magpie_debug.php and /scripts/magpie_simple.php page that if you send a specific https url in the RSS URL field, you are able to execute arbitrary commands.. EPSS estimates a 3.30% chance of exploitation in the next 30 days.

Description

Because of a incorrect escaped exec command in MagpieRSS in 0.72 in the /extlib/Snoopy.class.inc file, it is possible to add a extra command to the curl binary. This creates an issue on the /scripts/magpie_debug.php and /scripts/magpie_simple.php page that if you send a specific https url in the RSS URL field, you are able to execute arbitrary commands.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

3.30%

87.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-116

Affected Software

Vendor	Product	Versions
Magpierss Project	Magpierss	0.72

References

https://github.com/kellan/magpierss/blob/04d2a88b97fdba5813d01dc0d56c772d97360bb5/extlib/Snoopy.class.inc#L660Third Party Advisory
https://pastebin.com/kpzHKKJuExploit, Third Party Advisory
https://www.exploit-db.com/exploits/49643Exploit, Third Party Advisory, VDB Entry
https://github.com/kellan/magpierss/blob/04d2a88b97fdba5813d01dc0d56c772d97360bb5/extlib/Snoopy.class.inc#L660Third Party Advisory
https://pastebin.com/kpzHKKJuExploit, Third Party Advisory
https://www.exploit-db.com/exploits/49643Exploit, Third Party Advisory, VDB Entry

Timeline

Published: Apr 2, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-28940?

How severe is CVE-2021-28940?

CVE-2021-28940 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 3.30% probability of exploitation in the next 30 days.

How do I fix CVE-2021-28940?

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-2021-28940?

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

Scan your code now

Source: NVD / NIST