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.)
CWE-293 Variante Rascunho
Using Referer Field for Authentication
This vulnerability occurs when a web application uses the HTTP Referer header as a sole or primary method for authentication or authorization decisions. Since this header is entirely controlled by…
Definição
What is CWE-293?
This vulnerability occurs when a web application uses the HTTP Referer header as a sole or primary method for authentication or authorization decisions. Since this header is entirely controlled by the user's browser or client and can be easily forged, it provides no reliable security.
The HTTP Referer header is designed to tell a server which page a user came from, but it was never intended for security. Treating it as a trusted credential is like using a 'recommended by a friend' note for building access—anyone can write it. Developers might implement this check to prevent cross-site request forgery (CSRF) or to restrict direct URL access, but because attackers can fully manipulate the header with simple tools like a proxy or browser extension, this defense is completely ineffective.
To properly secure authentication and authorization, always use established server-side mechanisms like session tokens, CSRF tokens, or standard authentication protocols (OAuth, SAML). These methods rely on secrets or cryptographic signatures that the client cannot easily forge. Relying on the Referer header creates a false sense of security and leaves critical application functions exposed to trivial bypass attacks.
Impacto no mundo real
Real-world CVEs caused by CWE-293
Ainda não há referências CVE públicas associadas a este CWE no catálogo da MITRE.
Como os atacantes a exploram
Trajeto do atacante passo a passo
- 1
Identificar um caminho de código que trata input não confiável sem validação.
- 2
Criar um payload que explora o comportamento inseguro — injeção, traversal, overflow ou abuso de lógica.
- 3
Entregar o payload através de um pedido normal e observar a reação da aplicação.
- 4
Iterar até que a resposta exponha dados, execute código do atacante ou escale privilégios.
Exemplo de código vulnerável
Vulnerable C++
The following code samples check a packet's referer in order to decide whether or not an inbound request is from a trusted host.
String trustedReferer = "http://www.example.com/"
while(true){
n = read(newsock, buffer, BUFSIZE);
requestPacket = processPacket(buffer, n);
if (requestPacket.referer == trustedReferer){
openNewSecureSession(requestPacket);
}
} Exemplo de código seguro
Secure pseudo
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
const safe = validateAndEscape(input);
return executeWithGuards(safe);
} What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Lista de verificação de prevenção
How to prevent CWE-293
- Architecture and Design In order to usefully check if a given action is authorized, some means of strong authentication and method protection must be used. Use other means of authorization that cannot be simply spoofed. Possibilities include a username/password or certificate.
Sinais de deteção
How to detect CWE-293
CWE-293
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Perguntas frequentes O que é o CWE-293?
Qual a gravidade do CWE-293?
Que linguagens ou plataformas são afetadas pelo CWE-293?
Como posso prevenir o CWE-293?
Como é que o Plexicus deteta e corrige o CWE-293?
Onde posso saber mais sobre o CWE-293?
Frequently asked questions
O que é o CWE-293?
This vulnerability occurs when a web application uses the HTTP Referer header as a sole or primary method for authentication or authorization decisions. Since this header is entirely controlled by the user's browser or client and can be easily forged, it provides no reliable security.
Qual a gravidade do CWE-293?
A MITRE classifica a probabilidade de exploração como Alta — esta fraqueza é ativamente explorada em campo e deve ser priorizada para remediação.
Que linguagens ou plataformas são afetadas pelo CWE-293?
A MITRE não especificou as plataformas afetadas por este CWE — pode aplicar-se à maioria das stacks de aplicações.
Como posso prevenir o CWE-293?
In order to usefully check if a given action is authorized, some means of strong authentication and method protection must be used. Use other means of authorization that cannot be simply spoofed. Possibilities include a username/password or certificate.
Como é que o Plexicus deteta e corrige o CWE-293?
O motor SAST do Plexicus correlaciona a assinatura de fluxo de dados do CWE-293 em cada commit. Quando é encontrada uma correspondência, o nosso agente Codex Remedium abre um PR de correção com o código corrigido, testes e um resumo de uma linha para o revisor.
Onde posso saber mais sobre o CWE-293?
A MITRE publica a definição canónica em https://cwe.mitre.org/data/definitions/293.html. Pode também consultar a documentação da OWASP e do NIST para orientações adjacentes.
Fraquezas relacionadas
Weaknesses related to CWE-293
CWE-290 Pai
Authentication Bypass by Spoofing
This weakness occurs when an application's authentication system can be tricked into accepting forged or manipulated credentials, allowing…
CWE-291 Irmão
Reliance on IP Address for Authentication
This vulnerability occurs when a system uses a client's IP address as the sole or primary method to verify their identity.
CWE-350 Irmão
Reliance on Reverse DNS Resolution for a Security-Critical Action
This vulnerability occurs when an application uses a reverse DNS lookup on an IP address to get a hostname and then uses that hostname for…
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