The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.
N/A
Threat Mapped score: 0.0
Industry: Finiancial
Threat priority: Unclassified
CVE: CVE-2001-0950
Insufficiently random data used to generate session tokens using C rand(). Also, for certificate/key generation, uses a source that does not block when entropy is low.
CVE: CVE-2008-2108
Chain: insufficient precision (CWE-1339) in random-number generator causes some zero bits to be reliably generated, reducing the amount of entropy (CWE-331)
N/A
| Phase | Note |
|---|---|
| Architecture and Design | N/A |
| Implementation | REALIZATION: This weakness is caused during implementation of an architectural security tactic. |
Intro: This code generates a unique random identifier for a user's session.
Body: Because the seed for the PRNG is always the user's ID, the session ID will always be the same. An attacker could thus predict any user's session ID and potentially hijack the session.
function generateSessionID($userID){ srand($userID); return rand(); }Intro: 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.
Body: This code uses the Random.nextInt() function to generate "unique" identifiers for the receipt pages it generates. Because Random.nextInt() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.
String GenerateReceiptURL(String baseUrl) { Random ranGen = new Random(); ranGen.setSeed((new Date()).getTime()); return(baseUrl + ranGen.nextInt(400000000) + ".html"); }