FKIE_CVE-2019-12520
Vulnerability from fkie_nvd - Published: 2020-04-15 20:15 - Updated: 2024-11-21 04:23
Severity ?
Summary
An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI.
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| squid-cache | squid | * | |
| canonical | ubuntu_linux | 16.04 | |
| canonical | ubuntu_linux | 18.04 | |
| debian | debian_linux | 9.0 | |
| debian | debian_linux | 10.0 |
{
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*",
"matchCriteriaId": "A5584C95-5CB1-4D45-8C05-633746AE2AB4",
"versionEndIncluding": "4.7",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
},
{
"nodes": [
{
"cpeMatch": [
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"criteria": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*",
"matchCriteriaId": "F7016A2A-8365-4F1A-89A2-7A19F2BCAE5B",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
"matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D",
"vulnerable": true
}
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}
]
},
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
"matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
"matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
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}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request. If found, it servers the request. The absolute URL can include the decoded UserInfo (username and password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to provide a username that has special characters to delimit the domain, and treat the rest of the URL as a path or query string. An attacker could first make a request to their domain using an encoded username, then when a request for the target domain comes in that decodes to the exact URL, it will serve the attacker\u0027s HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows an attacker to gain access to features that only reverse proxies can use, such as ESI."
},
{
"lang": "es",
"value": "Se descubri\u00f3 un problema en Squid versiones hasta 4.7 y 5. Cuando se recibe una petici\u00f3n, Squid comprueba su memoria cach\u00e9 para visualizar si puede servir una respuesta. Lo hace al realizar un hash MD5 de la URL absoluta de la petici\u00f3n. Si se encuentra, sirve la petici\u00f3n. La URL absoluta puede incluir la UserInfo decodificada (nombre de usuario y contrase\u00f1a) para determinados protocolos. Esta informaci\u00f3n decodificada se antepone al dominio. Esto permite a un atacante proporcionar un nombre de usuario que tenga caracteres especiales para delimitar el dominio y tratar el resto de la URL como una ruta o cadena de consulta. Un atacante podr\u00eda primero hacer una petici\u00f3n a su dominio usando un nombre de usuario codificado, luego, cuando llega una petici\u00f3n para el dominio objetivo que decodifica a la URL exacta, servir\u00e1 el HTML del atacante en lugar del HTML real. En los servidores de Squid que tambi\u00e9n act\u00faan como proxies inversos, esto permite a un atacante conseguir acceso a funcionalidades que solo los proxies inversos pueden utilizar, tal y como ESI."
}
],
"id": "CVE-2019-12520",
"lastModified": "2024-11-21T04:23:01.370",
"metrics": {
"cvssMetricV2": [
{
"acInsufInfo": false,
"baseSeverity": "MEDIUM",
"cvssData": {
"accessComplexity": "LOW",
"accessVector": "NETWORK",
"authentication": "NONE",
"availabilityImpact": "NONE",
"baseScore": 5.0,
"confidentialityImpact": "PARTIAL",
"integrityImpact": "NONE",
"vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
"version": "2.0"
},
"exploitabilityScore": 10.0,
"impactScore": 2.9,
"obtainAllPrivilege": false,
"obtainOtherPrivilege": false,
"obtainUserPrivilege": false,
"source": "nvd@nist.gov",
"type": "Primary",
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
"version": "3.1"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2020-04-15T20:15:13.520",
"references": [
{
"source": "cve@mitre.org",
"tags": [
"Release Notes",
"Vendor Advisory"
],
"url": "http://www.squid-cache.org/Versions/v4/"
},
{
"source": "cve@mitre.org",
"tags": [
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"url": "http://www.squid-cache.org/Versions/v4/changesets/"
},
{
"source": "cve@mitre.org",
"tags": [
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"Third Party Advisory"
],
"url": "https://github.com/squid-cache/squid/commits/v4"
},
{
"source": "cve@mitre.org",
"tags": [
"Third Party Advisory"
],
"url": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt"
},
{
"source": "cve@mitre.org",
"tags": [
"Mailing List",
"Third Party Advisory"
],
"url": "https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html"
},
{
"source": "cve@mitre.org",
"tags": [
"Third Party Advisory"
],
"url": "https://security.netapp.com/advisory/ntap-20210205-0006/"
},
{
"source": "cve@mitre.org",
"tags": [
"Third Party Advisory"
],
"url": "https://usn.ubuntu.com/4446-1/"
},
{
"source": "cve@mitre.org",
"tags": [
"Third Party Advisory"
],
"url": "https://www.debian.org/security/2020/dsa-4682"
},
{
"source": "af854a3a-2127-422b-91ae-364da2661108",
"tags": [
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],
"url": "http://www.squid-cache.org/Versions/v4/"
},
{
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"tags": [
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"url": "http://www.squid-cache.org/Versions/v4/changesets/"
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"url": "https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12520.txt"
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"tags": [
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"url": "https://security.netapp.com/advisory/ntap-20210205-0006/"
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{
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"tags": [
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"url": "https://www.debian.org/security/2020/dsa-4682"
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],
"sourceIdentifier": "cve@mitre.org",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-20"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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