CVE-2021-26929
Estado: ModificadaMedia (6.1)—
An XSS issue was discovered in Horde Groupware Webmail Edition through 5.2.22 (where the Horde_Text_Filter library before 2.3.7 is used). The attacker can send a plain text e-mail message, with JavaScript encoded as a link or email that is mishandled by preProcess in Text2html.php, because bespoke use of \x00\x00\x00 and \x01\x01\x01 interferes with XSS defenses.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- Puntuación base: 6.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 4.94%
- Percentil entre todas las CVEs puntuadas: 92
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (2)
CWE
- CWE-79
Referencias
- http://packetstormsecurity.com/files/162187/Webmail-Edition-5.2.22-XSS-Remote-Code-Execution.html
- http://packetstormsecurity.com/files/162194/Horde-Groupware-Webmail-5.2.22-Cross-Site-Scripting.html
- https://github.com/horde/webmail/releases
- https://lists.debian.org/debian-lts-announce/2021/02/msg00028.html
- https://lists.horde.org/archives/announce/2021/001298.html
- https://www.alexbirnberg.com/horde-xss.html
- https://www.horde.org/apps/webmail
- http://packetstormsecurity.com/files/162187/Webmail-Edition-5.2.22-XSS-Remote-Code-Execution.html
- http://packetstormsecurity.com/files/162194/Horde-Groupware-Webmail-5.2.22-Cross-Site-Scripting.html
- https://github.com/horde/webmail/releases
- https://lists.debian.org/debian-lts-announce/2021/02/msg00028.html
- https://lists.horde.org/archives/announce/2021/001298.html
- https://www.alexbirnberg.com/horde-xss.html
- https://www.horde.org/apps/webmail
JSON original (NVD)
Mostrar
{
"id": "CVE-2021-26929",
"cveTags": [],
"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
}
]
},
"affected": [
{
"source": "cve@mitre.org",
"affectedData": [
{
"vendor": "n/a",
"product": "n/a",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
]
}
],
"published": "2021-02-14T04:15:12.777",
"references": [
{
"url": "http://packetstormsecurity.com/files/162187/Webmail-Edition-5.2.22-XSS-Remote-Code-Execution.html",
"tags": [
"Exploit",
"Third Party Advisory",
"VDB Entry"
],
"source": "cve@mitre.org"
},
{
"url": "http://packetstormsecurity.com/files/162194/Horde-Groupware-Webmail-5.2.22-Cross-Site-Scripting.html",
"tags": [
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://github.com/horde/webmail/releases",
"tags": [
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://lists.debian.org/debian-lts-announce/2021/02/msg00028.html",
"tags": [
"Mailing List",
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://lists.horde.org/archives/announce/2021/001298.html",
"tags": [
"Mailing List",
"Vendor Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://www.alexbirnberg.com/horde-xss.html",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://www.horde.org/apps/webmail",
"tags": [
"Vendor Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "http://packetstormsecurity.com/files/162187/Webmail-Edition-5.2.22-XSS-Remote-Code-Execution.html",
"tags": [
"Exploit",
"Third Party Advisory",
"VDB Entry"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://packetstormsecurity.com/files/162194/Horde-Groupware-Webmail-5.2.22-Cross-Site-Scripting.html",
"tags": [
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://github.com/horde/webmail/releases",
"tags": [
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://lists.debian.org/debian-lts-announce/2021/02/msg00028.html",
"tags": [
"Mailing List",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://lists.horde.org/archives/announce/2021/001298.html",
"tags": [
"Mailing List",
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.alexbirnberg.com/horde-xss.html",
"tags": [
"Exploit",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.horde.org/apps/webmail",
"tags": [
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-79"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "An XSS issue was discovered in Horde Groupware Webmail Edition through 5.2.22 (where the Horde_Text_Filter library before 2.3.7 is used). The attacker can send a plain text e-mail message, with JavaScript encoded as a link or email that is mishandled by preProcess in Text2html.php, because bespoke use of \\x00\\x00\\x00 and \\x01\\x01\\x01 interferes with XSS defenses."
},
{
"lang": "es",
"value": "Se detectó un problema de tipo XSS en Horde Groupware Webmail Edition versiones hasta 5.2.22 (donde es usada la biblioteca Horde_Text_Filter versiones anteriores a 2.3.7). El atacante puede enviar un mensaje de correo electrónico de texto plano, con JavaScript codificado como un enlace o correo electrónico que es manejado apropiadamente por la función preProcess en el archivo Text2html.php, porque el uso personalizado de \\x00\\x00\\x00 y \\x01\\x01\\x01 interfiere con las defensas de XSS"
}
],
"lastModified": "2026-06-17T03:44:01.673",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:horde:groupware:*:*:*:*:webmail:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9B749CF0-3995-4FFF-BA34-35D7C889AD78",
"versionEndIncluding": "5.2.22"
}
],
"operator": "OR"
}
]
},
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "cve@mitre.org"
}