CVE-2021-3618

ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certificates, such as multi-domain or wildcard certificates. A MiTM attacker having access to victim's traffic at the TCP/IP layer can redirect traffic from one subdomain to another, resulting in a valid TLS session. This breaks the authentication of TLS and cross-protocol attacks may be possible where the behavior of one protocol service may compromise the other at the application layer.

CVSS v3.0 7.4 HIGH
CVSS v2.0 5.8 MEDIUM

7.4^/10

CVSS v3.0 : HIGH

Vector :

Exploitability : 2.2 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

5.8^/10

CVSS v2.0 : MEDIUM

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

Exploitability : 8.6 / Impact : 4.9

Access Vector NETWORK

Access Complexity MEDIUM

Authentication NONE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact NONE

References

Link	Resource
https://bugzilla.redhat.com/show_bug.cgi?id=1975623	Issue Tracking Patch Third Party Advisory
https://alpaca-attack.com/	Third Party Advisory
https://lists.debian.org/debian-lts-announce/2022/11/msg00031.html	Mailing List Third Party Advisory

Advertisement

Configurations

Configuration 1 (hide)

cpe:2.3:a:f5:nginx:*:*:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:a:sendmail:sendmail:*:*:*:*:*:*:*:*

Configuration 3 (hide)

cpe:2.3:a:vsftpd_project:vsftpd:*:*:*:*:*:*:*:*

Configuration 4 (hide)

OR	cpe:2.3:o:fedoraproject:fedora:33:::::::*
	cpe:2.3:o:fedoraproject:fedora:34:::::::*
	cpe:2.3:o:fedoraproject:fedora:35:::::::*

Configuration 5 (hide)

cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

Information

Published : 2022-03-23 13:15

Updated : 2023-02-08 18:03

NVD link : CVE-2021-3618

Mitre link : CVE-2021-3618

JSON object : View

CWE

CWE-295

Improper Certificate Validation

Advertisement

Products Affected

f5

nginx

fedoraproject

fedora

vsftpd_project

vsftpd

debian

debian_linux

sendmail

sendmail

{"cve": {"data_type": "CVE", "references": {"reference_data": [{"url": "https://bugzilla.redhat.com/show_bug.cgi?id=1975623", "name": "https://bugzilla.redhat.com/show_bug.cgi?id=1975623", "tags": ["Issue Tracking", "Patch", "Third Party Advisory"], "refsource": "MISC"}, {"url": "https://alpaca-attack.com/", "name": "https://alpaca-attack.com/", "tags": ["Third Party Advisory"], "refsource": "MISC"}, {"url": "https://lists.debian.org/debian-lts-announce/2022/11/msg00031.html", "name": "[debian-lts-announce] 20221122 [SECURITY] [DLA 3203-1] nginx security update", "tags": ["Mailing List", "Third Party Advisory"], "refsource": "MLIST"}]}, "data_format": "MITRE", "description": {"description_data": [{"lang": "en", "value": "ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certificates, such as multi-domain or wildcard certificates. A MiTM attacker having access to victim's traffic at the TCP/IP layer can redirect traffic from one subdomain to another, resulting in a valid TLS session. This breaks the authentication of TLS and cross-protocol attacks may be possible where the behavior of one protocol service may compromise the other at the application layer."}]}, "problemtype": {"problemtype_data": [{"description": [{"lang": "en", "value": "CWE-295"}]}]}, "data_version": "4.0", "CVE_data_meta": {"ID": "CVE-2021-3618", "ASSIGNER": "secalert@redhat.com"}}, "impact": {"baseMetricV2": {"cvssV2": {"version": "2.0", "baseScore": 5.8, "accessVector": "NETWORK", "vectorString": "AV:N/AC:M/Au:N/C:P/I:P/A:N", "authentication": "NONE", "integrityImpact": "PARTIAL", "accessComplexity": "MEDIUM", "availabilityImpact": "NONE", "confidentialityImpact": "PARTIAL"}, "severity": "MEDIUM", "acInsufInfo": false, "impactScore": 4.9, "obtainAllPrivilege": false, "exploitabilityScore": 8.6, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}, "baseMetricV3": {"cvssV3": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.4, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 2.2}}, "publishedDate": "2022-03-23T20:15Z", "configurations": {"nodes": [{"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:a:f5:nginx:*:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true, "versionEndExcluding": "1.21.0"}]}, {"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:a:sendmail:sendmail:*:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true, "versionEndExcluding": "8.17"}]}, {"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:a:vsftpd_project:vsftpd:*:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true, "versionEndExcluding": "3.0.4"}]}, {"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true}, {"cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true}, {"cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true}]}, {"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*", "cpe_name": [], "vulnerable": true}]}], "CVE_data_version": "4.0"}, "lastModifiedDate": "2023-02-09T02:03Z"}