Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)

The JS Compute Runtime for Fastly's Compute@Edge platform provides the environment JavaScript is executed in when using the Compute@Edge JavaScript SDK. In versions prior to 0.5.3, the `Math.random` and `crypto.getRandomValues` methods fail to use sufficiently random values. The initial value to seed the PRNG (pseudorandom number generator) is baked-in to the final WebAssembly module, making the sequence of random values for that specific WebAssembly module predictable. An attacker can use the fixed seed to predict random numbers generated by these functions and bypass cryptographic security controls, for example to disclose sensitive data encrypted by functions that use these generators. The problem has been patched in version 0.5.3. No known workarounds exist.Show less

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. All versions of Argo CD starting with v0.11.0 are vulnerable to a variety of attacks when an SSO login is initiated from the Argo CD CLI or UI. The vulnerabilities are due to the use of insufficiently random values in parameters in Oauth2/OIDC login flows. In each case, using a relatively-predictable (time-based) seed in a non-cryptographically-secure pseudo-random number generator made the parameter less random than required by the relevant spec or by general best practices. In some cases, using too short a value made the entropy even less sufficient. The attacks on login flows which are meant to be mitigated by these parameters are difficult to accomplish but can have a high impact potentially granting an attacker admin access to Argo CD. Patches for this vulnerability has been released in the following Argo CD versions: v2.4.1, v2.3.5, v2.2.10 and v2.1.16. There are no known workarounds for this vulnerability.Show less

Piwigo is image gallery software written in PHP. When a criteria is not met on a host, piwigo defaults to usingmt_rand in order to generate password reset tokens. mt_rand output can be predicted after recovering the seed used to generate it. This low an unauthenticated attacker to take over an account providing they know an administrators email address in order to be able to request password reset.Show less

Telenot CompasX versions prior to 32.0 use a weak seed for random number generation leading to predictable AES keys used in the NFC tags used for local authorization of users. This may lead to total loss of trustworthiness of the installation.Show less

keypair is a a RSA PEM key generator written in javascript. keypair implements a lot of cryptographic primitives on its own or by borrowing from other libraries where possible, including node-forge. An issue was discovered where this library was generating identical RSA keys used in SSH. This would mean that the library is generating identical P, Q (and thus N) values which, in practical terms, is impossible with RSA-2048 keys. Generating identical values, repeatedly, usually indicates an issue with poor random number generation, or, poor handling of CSPRNG output. Issue 1: Poor random number generation (`GHSL-2021-1012`). The library does not rely entirely on a platform provided CSPRNG, rather, it uses it's own counter-based CMAC approach. Where things go wrong is seeding the CMAC implementation with "true" random data in the function `defaultSeedFile`. In order to seed the AES-CMAC generator, the library will take two different approaches depending on the JavaScript execution environment. In a browser, the library will use [`window.crypto.getRandomValues()`](https://github.com/juliangruber/keypair/blob/87c62f255baa12c1ec4f98a91600f82af80be6db/index.js#L971). However, in a nodeJS execution environment, the `window` object is not defined, so it goes down a much less secure solution, also of which has a bug in it. It does look like the library tries to use node's CSPRNG when possible unfortunately, it looks like the `crypto` object is null because a variable was declared with the same name, and set to `null`. So the node CSPRNG path is never taken. However, when `window.crypto.getRandomValues()` is not available, a Lehmer LCG random number generator is used to seed the CMAC counter, and the LCG is seeded with `Math.random`. While this is poor and would likely qualify in a security bug in itself, it does not explain the extreme frequency in which duplicate keys occur. The main flaw: The output from the Lehmer LCG is encoded incorrectly. The specific [line][https://github.com/juliangruber/keypair/blob/87c62f255baa12c1ec4f98a91600f82af80be6db/index.js#L1008] with the flaw is: `b.putByte(String.fromCharCode(next & 0xFF))` The [definition](https://github.com/juliangruber/keypair/blob/87c62f255baa12c1ec4f98a91600f82af80be6db/index.js#L350-L352) of `putByte` is `util.ByteBuffer.prototype.putByte = function(b) {this.data += String.fromCharCode(b);};`. Simplified, this is `String.fromCharCode(String.fromCharCode(next & 0xFF))`. The double `String.fromCharCode` is almost certainly unintentional and the source of weak seeding. Unfortunately, this does not result in an error. Rather, it results most of the buffer containing zeros. Since we are masking with 0xFF, we can determine that 97% of the output from the LCG are converted to zeros. The only outputs that result in meaningful values are outputs 48 through 57, inclusive. The impact is that each byte in the RNG seed has a 97% chance of being 0 due to incorrect conversion. When it is not, the bytes are 0 through 9. In summary, there are three immediate concerns: 1. The library has an insecure random number fallback path. Ideally the library would require a strong CSPRNG instead of attempting to use a LCG and `Math.random`. 2. The library does not correctly use a strong random number generator when run in NodeJS, even though a strong CSPRNG is available. 3. The fallback path has an issue in the implementation where a majority of the seed data is going to effectively be zero. Due to the poor random number generation, keypair generates RSA keys that are relatively easy to guess. This could enable an attacker to decrypt confidential messages or gain authorized access to an account belonging to the victim.Show less

Protectimus SLIM NFC 70 10.01 devices allow a Time Traveler attack in which attackers can predict TOTP passwords in certain situations. The time value used by the device can be set independently from the used seed value for generating time-based one-time passwords, without authentication. Thus, an attacker with short-time physical access to a device can set the internal real-time clock (RTC) to the future, generate one-time passwords, and reset the clock to the current time. This allows the generation of valid future time-based one-time passwords without having further access to the hardware token.Show less

A predictable seed vulnerability exists in the password reset functionality of Epignosis EfrontPro 5.2.21. By predicting the seed it is possible to generate the correct password reset 1-time token. An attacker can visit the password reset supplying the password reset token to reset the password of an account of their choice.Show less

Elastic Cloud on Kubernetes (ECK) versions prior to 1.1.0 generate passwords using a weak random number generator. If an attacker is able to determine when the current Elastic Stack cluster was deployed they may be able to more easily brute force the Elasticsearch credentials generated by ECK.Show less

In Couchbase Server 5.1.1, the cookie used for intra-node communication was not generated securely. Couchbase Server uses erlang:now() to seed the PRNG which results in a small search space for potential random seeds that could then be used to brute force the cookie and execute code against a remote system. This has been fixed in version 6.0.0.Show less

When handling a SSLv2-compatible ClientHello request, the server doesn't generate a new random value but sends an all-zero value instead. This results in full malleability of the ClientHello for SSLv2 used for TLS 1.2 in all versions prior to NSS 3.39. This does not impact TLS 1.3.Show less

In Airsonic 10.2.1, RecoverController.java generates passwords via org.apache.commons.lang.RandomStringUtils, which uses java.util.Random internally. This PRNG has a 48-bit seed that can easily be bruteforced, leading to trivial privilege escalation attacks.Show less

Python's elementtree C accelerator failed to initialise Expat's hash salt during initialization. This could make it easy to conduct denial of service attacks against Expat by constructing an XML document that would cause pathological hash collisions in Expat's internal data structures, consuming large amounts CPU and RAM. The vulnerability exists in Python versions 3.7.0, 3.6.0 through 3.6.6, 3.5.0 through 3.5.6, 3.4.0 through 3.4.9, 2.7.0 through 2.7.15.Show less

An issue was discovered in ntopng 3.4 before 3.4.180617. The PRNG involved in the generation of session IDs is not seeded at program startup. This results in deterministic session IDs being allocated for active user sessions. An attacker with foreknowledge of the operating system and standard library in use by the host running the service and the username of the user whose session they're targeting can abuse the deterministic random number generation in order to hijack the user's session, thus escalating their access.Show less

IBM GSKit (IBM DB2 for Linux, UNIX and Windows 9.7, 10.1, 10.5, and 11.1) duplicates the PRNG state across fork() system calls when multiple ICC instances are loaded which could result in duplicate Session IDs and a risk of duplicate key material. IBM X-Force ID: 139071.Show less