Open redirect: xfinity.com

 1name: "Open redirect: xfinity.com"
 2description: |
 3    Message contains use of the xfinity.com open redirect. This has been exploited in the wild.
 4type: "rule"
 5severity: "medium"
 6source: |
 7    type.inbound
 8    and any(body.links,
 9            .href_url.domain.root_domain == "xfinity.com"
10            and strings.icontains(.href_url.path, "/learn/cima/login")
11            and strings.icontains(.href_url.query_params, "referer=")
12            and not regex.icontains(.href_url.query_params,
13                                    'referer=(?:https?)?(?:(?:%3a|\:)?(?:\/|%2f){2})?xfinity\.com+'
14            )
15    )
16    and not sender.email.domain.root_domain in ("xfinity.com", "comcast.net")
17
18    // negate highly trusted sender domains unless they fail DMARC authentication
19    and (
20    (
21        sender.email.domain.root_domain in $high_trust_sender_root_domains
22        and not headers.auth_summary.dmarc.pass
23    )
24    or sender.email.domain.root_domain not in $high_trust_sender_root_domains
25    )    
26attack_types:
27  - "Credential Phishing"
28  - "Malware/Ransomware"
29tactics_and_techniques:
30  - "Open redirect"
31detection_methods:
32  - "Sender analysis"
33  - "URL analysis"
34id: "7b9012fa-0f14-57d5-b729-cb3b84565c47"