| Titolo | The Trusted Domain Project OpenDMARC 1.4.2 Improper Authentication |
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| Descrizione | OpenDMARC 1.4.2 fails to normalize certain Unicode characters in the domain of the visible `From:` address before performing a DMARC policy lookup. A crafted domain containing a Unicode character that maps to an ASCII domain separator, such as a fullwidth full stop, may therefore be treated as a different and policy-less domain. OpenDMARC returns `dmarc=none` instead of applying the DMARC policy published for the corresponding ASCII domain.
A remote unauthenticated attacker can exploit this issue by sending a forged message whose `From:` domain visually resembles a protected domain but uses such a Unicode character. No signing key or control of the victim’s DNS records is required. As a result, a published `p=reject` or `p=quarantine` policy may be bypassed, increasing the risk of email impersonation and phishing. |
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| Fonte | ⚠️ https://weitongli.com/share/opendmarc-unicode-dot-bypass.html |
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| Utente | WeitongLi (UID 100239) |
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| Sottomissione | 06/08/2026 12:53 (2 mesi fa) |
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| Moderazione | 27/09/2026 13:33 (2 months later) |
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| Stato | Accettato |
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| Voce VulDB | 410885 [Trusted Domain Project OpenDMARC fino a 1.4.2 policy.c Esecuzione di codice remoto] |
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| Punti | 20 |
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