HOMEVULNERABILITIESCVE-2021-28940
CRITICAL

CVE-2021-28940

CWE-116Published: April 2, 2021· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-28940 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

magpierss_project1 product(s)
magpierss
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://github.com/kellan/magpierss/blob/04d2a88b97fdba5813d01dc0d56c772d97360bb5/extlib/Snoopy.class.inc#L660
ADVISORYhttps://pastebin.com/kpzHKKJu
ADVISORYhttps://www.exploit-db.com/exploits/49643
ADVISORYhttps://github.com/kellan/magpierss/blob/04d2a88b97fdba5813d01dc0d56c772d97360bb5/extlib/Snoopy.class.inc#L660
ADVISORYhttps://pastebin.com/kpzHKKJu
ADVISORYhttps://www.exploit-db.com/exploits/49643

All References (6)

→
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

Quick Facts

CVE IDCVE-2021-28940
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-116
CISA KEVNo
Affected1 vendor(s)
PublishedApr 2, 2021

Related CVEs (CWE-116)

CVE-2026-48358
10.0
CVE-2025-55729
10.0
CVE-2025-55730
10.0
CVE-2020-36599
9.8
CVE-2017-8303
9.8
CVE-2018-9246
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-28940 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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