How severe is CVE-2021-28940?

CVE-2021-28940 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-28940 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28940?

CVE-2021-28940 affects Magpierss Project Magpierss. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-28940?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-28940 published?

CVE-2021-28940 was published on 2021-04-02 and last updated on 2026-06-17.

CVE-2021-28940

CVE-2021-28940 is a critical-severity vulnerability in Magpierss Project Magpierss with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-116.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-116
Affected product: Magpierss Project Magpierss
Published: 2021-04-02
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-28940?: 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.
How severe is CVE-2021-28940?: CVE-2021-28940 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-28940 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28940?: CVE-2021-28940 affects Magpierss Project Magpierss. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-28940?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-28940 published?: CVE-2021-28940 was published on 2021-04-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:magpierss_project:magpierss:0.72:*:*:*:*:*:*:*

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