In Claws Mail 3.14.1, an attacker in possession of S/MIME or PGP encrypted emails can wrap them as sub-parts within a crafted multipart email. The encrypted part(s) can further be hidden using HTML/CSS or ASCII newline characters. This modified multipart email can be re-sent by the attacker to the intended receiver. If the receiver replies to this (benign looking) email, they unknowingly leak the plaintext of the encrypted message part(s) back to the attacker.
The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Claws-mail | 3.14.1 (including) | 3.14.1 (including) | |
| Claws-mail | Ubuntu | bionic | * |
| Claws-mail | Ubuntu | cosmic | * |
| Claws-mail | Ubuntu | disco | * |
| Claws-mail | Ubuntu | eoan | * |
| Claws-mail | Ubuntu | groovy | * |
| Claws-mail | Ubuntu | hirsute | * |
| Claws-mail | Ubuntu | impish | * |
| Claws-mail | Ubuntu | kinetic | * |
| Claws-mail | Ubuntu | lunar | * |
| Claws-mail | Ubuntu | mantic | * |
| Claws-mail | Ubuntu | trusty | * |
| Claws-mail | Ubuntu | xenial | * |
Many communication channels can be “sniffed” (monitored) by adversaries during data transmission. For example, in networking, packets can traverse many intermediary nodes from the source to the destination, whether across the internet, an internal network, the cloud, etc. Some actors might have privileged access to a network interface or any link along the channel, such as a router, but they might not be authorized to collect the underlying data. As a result, network traffic could be sniffed by adversaries, spilling security-critical data. Applicable communication channels are not limited to software products. Applicable channels include hardware-specific technologies such as internal hardware networks and external debug channels, supporting remote JTAG debugging. When mitigations are not applied to combat adversaries within the product’s threat model, this weakness significantly lowers the difficulty of exploitation by such adversaries. When full communications are recorded or logged, such as with a packet dump, an adversary could attempt to obtain the dump long after the transmission has occurred and try to “sniff” the cleartext from the recorded communications in the dump itself.