CAPEC-145: Checksum Spoofing

An adversary spoofs a checksum message for the purpose of making a payload appear to have a valid corresponding checksum. Checksums are used to verify message integrity. They consist of some value based on the value of the message they are protecting. Hash codes are a common checksum mechanism. Both the sender and recipient are able to compute the checksum based on the contents of the message. If the message contents change between the sender and recipient, the sender and recipient will compute different checksum values. Since the sender's checksum value is transmitted with the message, the recipient would know that a modification occurred. In checksum spoofing an adversary modifies the message body and then modifies the corresponding checksum so that the recipient's checksum calculation will match the checksum (created by the adversary) in the message. This would prevent the recipient from realizing that a change occurred.

Comment

We don't cover checksums in the input that a component accepts, since this is covered by different threats.

Medium
Severity
4
occurrences in scenarios
Frequency
1
Affected Components
4
Affected Scenarios

Requirements and Mitigations

Requirements

Component properties that must be true for this threat to apply:

Mitigations

Component properties that mitigate this threat:

Affected Components

Component Description Boundary
Build machines Build machines (Mac minis) operated by FPF Infra FPF-operated Tailnet

Affected Scenarios

release — affects: Build machines
release_basic — affects: Build machines
release_signatures — affects: Build machines
release_sandbox — affects: Build machines

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