CVE-2021-21259

HedgeDoc is open source software which lets you create real-time collaborative markdown notes. In HedgeDoc before version 1.7.2, an attacker can inject arbitrary JavaScript into a HedgeDoc note, which is executed when the note is viewed in slide mode. Depending on the configuration of the instance, the attacker may not need authentication to create or edit notes. The problem is patched in HedgeDoc 1.7.2. As a workaround, disallow loading JavaScript from 3rd party sites using the `Content-Security-Policy` header. Note that this will break some embedded content.

CVSS v3 6.1 MEDIUM
CVSS v2.0 4.3 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

4.3^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:M/Au:N/C:N/I:P/A:N

Exploitability : 8.6 / Impact : 2.9

Access Vector NETWORK

Access Complexity MEDIUM

Authentication NONE

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact NONE

References

Link	Resource
https://github.com/hackmdio/codimd/issues/1648	Exploit Patch Third Party Advisory
https://github.com/hedgedoc/hedgedoc/commit/35b0d39a12aa35f27fba8c1f50b1886706e7efef	Patch Third Party Advisory
https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.2	Release Notes Third Party Advisory
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-44w9-vm8p-3cxw	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:hedgedoc:hedgedoc:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2021-01-22 17:15

Updated : 2024-02-28 18:08

NVD link : CVE-2021-21259

Mitre link : CVE-2021-21259

CVE.ORG link : CVE-2021-21259

JSON object : View

Products Affected

hedgedoc

hedgedoc

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

{"id": "CVE-2021-21259", "metrics": {"cvssMetricV2": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"version": "2.0", "baseScore": 4.3, "accessVector": "NETWORK", "vectorString": "AV:N/AC:M/Au:N/C:N/I:P/A:N", "authentication": "NONE", "integrityImpact": "PARTIAL", "accessComplexity": "MEDIUM", "availabilityImpact": "NONE", "confidentialityImpact": "NONE"}, "acInsufInfo": false, "impactScore": 2.9, "baseSeverity": "MEDIUM", "obtainAllPrivilege": false, "exploitabilityScore": 8.6, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": true}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 6.1, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 2.7, "exploitabilityScore": 2.8}, {"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 7.4, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 4.0, "exploitabilityScore": 2.8}]}, "published": "2021-01-22T17:15:12.867", "references": [{"url": "https://github.com/hackmdio/codimd/issues/1648", "tags": ["Exploit", "Patch", "Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/hedgedoc/hedgedoc/commit/35b0d39a12aa35f27fba8c1f50b1886706e7efef", "tags": ["Patch", "Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.2", "tags": ["Release Notes", "Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-44w9-vm8p-3cxw", "tags": ["Third Party Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-79"}]}], "descriptions": [{"lang": "en", "value": "HedgeDoc is open source software which lets you create real-time collaborative markdown notes. In HedgeDoc before version 1.7.2, an attacker can inject arbitrary JavaScript into a HedgeDoc note, which is executed when the note is viewed in slide mode. Depending on the configuration of the instance, the attacker may not need authentication to create or edit notes. The problem is patched in HedgeDoc 1.7.2. As a workaround, disallow loading JavaScript from 3rd party sites using the `Content-Security-Policy` header. Note that this will break some embedded content."}, {"lang": "es", "value": "HedgeDoc es un software de c\u00f3digo abierto que permite crear notas markdown colaborativas en tiempo real. En HedgeDoc antes de la versi\u00f3n 1.7.2, un atacante puede inyectar JavaScript arbitrario en una nota de HedgeDoc, que se ejecuta cuando la nota se ve en modo de diapositivas. Dependiendo de la configuraci\u00f3n de la instancia, el atacante puede no necesitar autenticaci\u00f3n para crear o editar notas. El problema est\u00e1 parcheado en HedgeDoc versi\u00f3n 1.7.2. Como soluci\u00f3n, deshabilite la carga de JavaScript desde sitios de terceros utilizando la cabecera `Content-Security-Policy`. Tenga en cuenta que esto romper\u00e1 algunos contenidos incrustados"}], "lastModified": "2021-06-08T14:36:18.190", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:hedgedoc:hedgedoc:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6EF4EA31-5B63-4C26-A744-E8A8B03D8DEC", "versionEndExcluding": "1.7.2"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}