CWE-330 (使用不充分的随机数) — Vulnerability Class 126

126 vulnerabilities classified as CWE-330 (使用不充分的随机数). AI Chinese analysis included.

CWE-330 represents a critical weakness where software relies on predictable or insufficiently random values within security-sensitive contexts, such as session token generation or cryptographic key creation. Attackers typically exploit this flaw by analyzing patterns in the generated values to predict future outputs, thereby bypassing authentication mechanisms or hijacking active user sessions. This vulnerability often stems from the misuse of standard pseudo-random number generators that lack cryptographic security properties. To mitigate this risk, developers must employ cryptographically secure pseudo-random number generators (CSPRNGs) that are specifically designed to resist prediction even if previous outputs are known. Additionally, ensuring proper seeding with high-entropy sources and avoiding custom randomization algorithms are essential practices for maintaining the integrity of security-dependent operations.

MITRE CWE Description

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Common Consequences (3)

Confidentiality, Other Other

When a protection mechanism relies on random values to restrict access to a sensitive resource, such as a session ID or a seed for generating a cryptographic key, then the resource being protected could be accessed by guessing the ID or key.

Access Control, Other Bypass Protection Mechanism, Other

If product relies on unique, unguessable IDs to identify a resource, an attacker might be able to guess an ID for a resource that is owned by another user. The attacker could then read the resource, or pre-create a resource with the same ID to prevent the legitimate program from properly sending the…

Access Control Bypass Protection Mechanism, Gain Privileges or Assume Identity

When an authorization or authentication mechanism relies on random values to restrict access to restricted functionality, such as a session ID or a seed for generating a cryptographic key, then an attacker may access the restricted functionality by guessing the ID or key.

Mitigations (3)

Architecture and Design Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds. In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts. Pseudo-random number generators can produce…

Implementation Consider a PRNG that re-seeds itself as needed from high quality pseudo-random output sources, such as hardware devices.

Architecture and Design, Requirements Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").

Examples (2)

This code attempts to generate a unique random identifier for a user's session.

function generateSessionID($userID){ srand($userID); return rand(); }

Bad · PHP

The following code uses a statistical PRNG to create a URL for a receipt that remains active for some period of time after a purchase.

String GenerateReceiptURL(String baseUrl) { Random ranGen = new Random(); ranGen.setSeed((new Date()).getTime()); return(baseUrl + ranGen.nextInt(400000000) + ".html"); }

Bad · Java

CVE ID	Title	CVSS	Severity	Published
CVE-2018-17888	NUUO CMS 安全漏洞 — NUUO CMS	9.8	-	2018-10-12
CVE-2018-13280	Synology DiskStation Manager 安全漏洞 — DiskStation Manager (DSM)	7.4	-	2018-07-30
CVE-2017-16028	react-native-meteor-oauth 安全漏洞 — react-native-meteor-oauth node module	7.5	-	2018-06-04
CVE-2018-1108	Linux kernel驱动程安全特征问题漏洞 — drivers	6.5	-	2018-05-21
CVE-2017-6026	Schneider Electric Modicon PLCs Modicon M241和Modicon M251 安全特征问题漏洞 — Schneider Electric Modicon PLCs	9.1	-	2017-06-30
CVE-2017-0897	EllisLab ExpressionEngine 安全漏洞 — ExpressionEngine	7.5	-	2017-06-22

Vulnerabilities classified as CWE-330 (使用不充分的随机数) represent 126 CVEs. The CWE taxonomy describes the weakness; review individual CVEs for product-specific impact.