CWE-93 Improper Neutralization of CRLF Sequences

The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.

• Integrity: Modify Application Data

• [Implementation] Avoid using CRLF as a special sequence. • [Implementation] Appropriately filter or quote CRLF sequences in user-controlled input.

• Automated Static Analysis: Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

• CVE-2002-1771: CRLF injection enables spam proxy (add mail headers) using email address or name. • CVE-2002-1783: CRLF injection in API function arguments modify headers for outgoing requests. • CVE-2004-1513: Spoofed entries in web server log file via carriage returns • CVE-2006-4624: Chain: inject fake log entries with fake timestamps using CRLF injection • CVE-2005-1951: Chain: Application accepts CRLF in an object ID, allowing HTTP response splitting. • CVE-2004-1687: Chain: HTTP response splitting via CRLF in parameter related to URL.