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Fencer Intel
high 7.2

CVE-2020-13978 json

Monstra CMS 3.0.4 allows an attacker, who already has administrative access to modify .chunk.php files on the Edit Chunk screen, to execute…

published 6y ago modified 4mo ago also EUVD-2020-6149

cvss
7.2
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits
0
none known

Summary

Monstra CMS 3.0.4 allows an attacker, who already has administrative access to modify .chunk.php files on the Edit Chunk screen, to execute arbitrary OS commands via the Theme Module by visiting the admin/index.php?id=themes&action=edit_chunk URI. NOTE: there is no indication that the Edit Chunk feature was intended to prevent an administrator from using PHP's exec feature

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2y ago

Exploit prediction

1.27% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/monstra-cms/monstra/issues/464 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.2 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 6.5 AV:N/AC:L/Au:S/C:P/I:P/A:P

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.