CWE-807 (在安全决策中依赖未经信任的输入) — Vulnerability Class 68

68 vulnerabilities classified as CWE-807 (在安全决策中依赖未经信任的输入). AI Chinese analysis included.

CWE-807 represents a critical security weakness where a system’s protective mechanisms depend on untrusted inputs that attackers can manipulate to bypass defenses. This flaw typically arises when developers erroneously assume that client-side data, such as cookies, environment variables, or hidden form fields, remain immutable and trustworthy. Attackers exploit this vulnerability by modifying these inputs using customized clients or other interception techniques, effectively tricking the application into granting unauthorized access or executing privileged actions. To mitigate this risk, developers must never rely on client-side validation for security decisions. Instead, they should enforce strict server-side validation, implement robust authentication and authorization checks independent of user-supplied data, and treat all external inputs as potentially hostile. By decoupling security logic from untrusted sources, organizations can prevent attackers from circumventing protective measures through simple input tampering.

MITRE CWE Description

The product uses a protection mechanism that relies on the existence or values of an input, but the input can be modified by an untrusted actor in a way that bypasses the protection mechanism. Developers may assume that inputs such as cookies, environment variables, and hidden form fields cannot be modified. However, an attacker could change these inputs using customized clients or other attacks. This change might not be detected. When security decisions such as authentication and authorization are made based on the values of these inputs, attackers can bypass the security of the software. Without sufficient encryption, integrity checking, or other mechanism, any input that originates from an outsider cannot be trusted.

Common Consequences (1)

Confidentiality, Access Control, Availability, Other Bypass Protection Mechanism, Gain Privileges or Assume Identity, Varies by Context

Attackers can bypass the security decision to access whatever is being protected. The consequences will depend on the associated functionality, but they can range from granting additional privileges to untrusted users to bypassing important security checks. Ultimately, this weakness may lead to expo…

Mitigations (5)

Architecture and Design Store state information and sensitive data on the server side only. Ensure that the system definitively and unambiguously keeps track of its own state and user state and has rules defined for legitimate state transitions. Do not allow any application user to affect state directly in any way other than through legitimate actions leading to state transitions. If information must be stored on the cli…

Architecture and Design Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. With a stateless protocol such as HTTP, use a framework that maintains the state for you. Examples include ASP.NET View State [REF-756] and the OWASP ESAPI Session Management feature [REF-45]. Be careful of language features that provide state support, since …

Architecture and Design For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

Operation, Implementation When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.

Architecture and Design, Implementation Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly throug…

Examples (2)

The following code excerpt reads a value from a browser cookie to determine the role of the user.

Cookie[] cookies = request.getCookies(); for (int i =0; i< cookies.length; i++) { Cookie c = cookies[i]; if (c.getName().equals("role")) { userRole = c.getValue(); } }

Bad · Java

The following code could be for a medical records application. It performs authentication by checking if a cookie has been set.

$auth = $_COOKIES['authenticated']; if (! $auth) { if (AuthenticateUser($_POST['user'], $_POST['password']) == "success") { // save the cookie to send out in future responses setcookie("authenticated", "1", time()+60*60*2); } else { ShowLoginScreen(); die("\n"); } } DisplayMedicalHistory($_POST['patient_ID']);

Bad · PHP

CVE ID	Title	CVSS	Severity	Published
CVE-2022-24400	DCK pinning attack in TETRA — TETRA Standard	7.5	High	2023-10-19
CVE-2023-0009	GlobalProtect App: Local Privilege Escalation (PE) Vulnerability — GlobalProtect App	7.8	High	2023-06-14
CVE-2022-20744	Cisco Firepower Management Center Software Information Disclosure Vulnerability — Cisco Firepower Management Center	6.5	-	2022-05-03
CVE-2021-36777	login-proxy sends password to attacker-provided domain — Build service	8.1	High	2022-03-09
CVE-2021-31999	Rancher: Privilege escalation vulnerability via malicious Connection header — Rancher	8.8	High	2021-07-15
CVE-2021-29479	Cached redirect poisoning via X-Forwarded-Host header — ratpack	7.0	High	2021-06-29
CVE-2020-5252	Malicious package may avoid detection in python auditing — safety	5.0	Medium	2020-03-23
CVE-2017-0887	Nextcloud Server 安全漏洞 — Nextcloud Server	2.7	-	2017-04-05

Vulnerabilities classified as CWE-807 (在安全决策中依赖未经信任的输入) represent 68 CVEs. The CWE taxonomy describes the weakness; review individual CVEs for product-specific impact.