Authentication Bypass by Capture-replay

Description

A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).

Extended Description

Capture-replay attacks are common and can be difficult to defeat without cryptography. They are a subset of network injection attacks that rely on observing previously-sent valid commands, then changing them slightly if necessary and resending the same commands to the server.

Common Consequences 1

Scope: Access Control

Impact: Gain Privileges or Assume Identity

Messages sent with a capture-relay attack allow access to resources which are not otherwise accessible without proper authentication.

Potential Mitigations 2

Phase: Architecture and Design

Utilize some sequence or time stamping functionality along with a checksum which takes this into account in order to ensure that messages can be parsed only once.

Phase: Architecture and Design

Since any attacker who can listen to traffic can see sequence numbers, it is necessary to sign messages with some kind of cryptography to ensure that sequence numbers are not simply doctored along with content.

Observed Examples 2

CVE-2005-3435product authentication succeeds if user-provided MD5 hash matches the hash in its database; this can be subjected to replay attacks.

CVE-2007-4961Chain: cleartext transmission of the MD5 hash of password (Cleartext Transmission of Sensitive Information) enables attacks against a server that is susceptible to replay (Authentication Bypass by Capture-replay).

References 1

The CLASP Application Security Process

Secure Software, Inc.

2005

https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf(2024-11-17)

ID: REF-18