CVE-2021-21260
Status: ModifiedMedium (5.4)—
Online Invoicing System (OIS) is open source software which is a lean invoicing system for small businesses, consultants and freelancers created using AppGini. In OIS version 4.0 there is a stored XSS which can enables an attacker takeover of the admin account through a payload that extracts a csrf token and sends a request to change password. It has been found that Item description is reflected without sanitization in app/items_view.php which enables the malicious scenario.
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- Base score: 5.4
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 0.60%
- Percentile among all scored CVEs: 47
- Score date: 10/6/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
CWEs
- CWE-79
References
- https://github.com/bigprof-software/online-invoicing-system/releases/tag/4.2
- https://github.com/bigprof-software/online-invoicing-system/security/advisories/GHSA-rm79-5596-r7q4
- https://github.com/bigprof-software/online-invoicing-system/releases/tag/4.2
- https://github.com/bigprof-software/online-invoicing-system/security/advisories/GHSA-rm79-5596-r7q4
Raw JSON (NVD)
Show
{
"id": "CVE-2021-21260",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 3.5,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:M/Au:S/C:N/I:P/A:N",
"authentication": "SINGLE",
"integrityImpact": "PARTIAL",
"accessComplexity": "MEDIUM",
"availabilityImpact": "NONE",
"confidentialityImpact": "NONE"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "LOW",
"obtainAllPrivilege": false,
"exploitabilityScore": 6.8,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": true
}
],
"cvssMetricV31": [
{
"type": "Secondary",
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"cvssData": {
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"version": "3.1",
"baseScore": 7.6,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:H/A:N",
"integrityImpact": "HIGH",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "LOW",
"confidentialityImpact": "LOW"
},
"impactScore": 4.7,
"exploitabilityScore": 2.3
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
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"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "LOW",
"confidentialityImpact": "LOW"
},
"impactScore": 2.7,
"exploitabilityScore": 2.3
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "bigprof-software",
"product": "online-invoicing-system",
"versions": [
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"status": "affected",
"version": "= 4.0"
}
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}
]
}
],
"published": "2021-01-22T18:15:12.610",
"references": [
{
"url": "https://github.com/bigprof-software/online-invoicing-system/releases/tag/4.2",
"tags": [
"Third Party Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/bigprof-software/online-invoicing-system/security/advisories/GHSA-rm79-5596-r7q4",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/bigprof-software/online-invoicing-system/releases/tag/4.2",
"tags": [
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://github.com/bigprof-software/online-invoicing-system/security/advisories/GHSA-rm79-5596-r7q4",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-79"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Online Invoicing System (OIS) is open source software which is a lean invoicing system for small businesses, consultants and freelancers created using AppGini. In OIS version 4.0 there is a stored XSS which can enables an attacker takeover of the admin account through a payload that extracts a csrf token and sends a request to change password. It has been found that Item description is reflected without sanitization in app/items_view.php which enables the malicious scenario."
},
{
"lang": "es",
"value": "El Sistema de Facturación en Línea (OIS) es un software de código abierto que es un sistema de facturación ajustado para pequeñas empresas, consultores y autónomos creado con AppGini. En OIS versión 4.0 se presenta una vulnerabilidad de tipo XSS almacenado que puede permitir que un atacante tome el control de la cuenta de administrador por medio de una carga útil que extrae un token csrf y envía una petición para cambiar la contraseña. Se ha detectado que la descripción del artículo se refleja sin saneamiento en el archivo app/items_view.php, lo que habilita el escenario malicioso"
}
],
"lastModified": "2026-06-17T03:35:08.763",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:bigprof:online_invoicing_system:4.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "03A30130-6CAE-4330-95EF-8658D93EF4C4"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "security-advisories@github.com"
}