Draft in the CWE catalog · 96 CVEs mapped
The product has two different sources of the same data or information, but it uses the source that has less support for verification, is less trusted, or is less resistant to attack.
Use of a less trusted source for the envelope sender in the external-account download of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote unauthenticated attacker to have mail they write in the name of a domain the server hosts sent on by the server with an envelope sender at that domain, so that it passes the domain's SPF and DMARC at other receivers. A message the server downloads from an external POP3 or IMAP account has no SMTP envelope of its own, and the server took the address in its From header as its envelope sender, whatever that address was. A forward or redirect of the downloaded message to an outside address then left with that address as its envelope sender, which the Sender Rewriting Scheme leaves alone for a hosted domain, so that the receiver's SPF check passed for the forged domain, aligned even under strict alignment, with no non-default setting, host name record or DMARC policy needed. An attacker needs to know a mailbox elsewhere that an account here collects and forwards to an outside address; an account holder who adds an external account of their own can collect from a server of their own, which matters where SmtpAuthenticatedSenderCheck holds signed-in senders to their own addresses.
In the Golang Chi web framework, the ClientIPFromXFF middleware skips any X-Forwarded-For entry in a configured trusted CIDR but never verifies that the direct TCP peer in http.Request.RemoteAddr belongs to that CIDR. A client that can reach the Go server directly can therefore append a trusted-looking proxy address and choose the client IP returned by middleware.GetClientIP. This issue affects chi before 5.4.0.
Use of a less trusted source in the DKIM signing of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote unauthenticated attacker to have mail they write signed with the DKIM key of a domain the server hosts, so that it passes DKIM and DMARC for that domain at other receivers. With DKIM signing enabled for a hosted domain, the server signed every message on its first delivery pass as the domain named in its From header, before local delivery, whatever the message's origin and without checking that its sender had authenticated. A sender anywhere could therefore send the server, as ordinary inbound mail, a message whose From is any address at such a domain, and the server signed it with that domain's key. Every copy the server then sent on to an address outside carried a valid signature aligned with the forged From, whatever the domain's DMARC policy: an account's forward, a mail rule's forward or copy, a Sieve redirect, an alias or distribution list with an outside member, the mirror copy, a managed-list or journal copy, or a message released from quarantine. A signed copy can also be re-sent to other recipients while the domain's key is unchanged. Exploitation needs DKIM signing to be enabled for the hosted domain (it is off until configured) and, for the forgery to leave the server, a forward, alias, list or rule that carries the domain's mail to an outside address. The signer likewise signed a message submitted over authenticated SMTP as whatever hosted domain its From header named, a header authenticated SMTP does not hold to the submitting account, so that an account of one hosted domain could have mail written in the name of another hosted domain signed with that domain's key; this mattered where the server holds signed-in senders to their own envelope addresses (SmtpAuthenticatedSenderCheck, off by default), as the signature was then the remaining way for such mail to pass the other domain's DMARC policy.