Security advisory
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
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-13978
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 10:50 UTC · Revision 1
Source evidence
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
osv:CVE-2020-13978
Complete source record
{
"id": "20ab711121e8fbd764655ea5bcd527adb8a0891f9fa58784dd4db0b21e05e811",
"url": "https://osv.dev/vulnerability/CVE-2020-13978",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-13978",
"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",
"evidence": "osv:CVE-2020-13978",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2020-13978",
"aliases": [
"CVE-2020-13978"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/monstra-cms/monstra",
"type": "GIT",
"events": [
{
"introduced": "81bad8b6649253bd972ac4158816189d38366216"
},
{
"last_affected": "81bad8b6649253bd972ac4158816189d38366216"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:monstra:monstra_cms:3.0.4:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.0.4"
},
{
"last_affected": "3.0.4"
}
],
"source": "CPE_STRING"
}
]
}
}
],
"versions": [
"3.0.4",
"v3.0.4"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-13978.json"
}
}
],
"modified": "2026-10-20T10:51:48.772116106Z",
"provider": "osv",
"references": [
"https://github.com/monstra-cms/monstra/issues/464"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2020-13978",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 382981,
"published_at": "2020-06-09T14:15:10.14+00:00"
}