HTTP::Session2 versions before 1.12 for Perl for Perl may generate weak session ids using the rand() function. The HTTP::Session2 session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand() function is unsuitable for cryptographic usage. HTTP::Session2 after version 1.02 will attempt to use the /dev/urandom device to generate a session id, but if the device is unavailable (for example, under Windows), then it will revert to the insecure method described above.

Apache::SessionX versions through 2.01 for Perl create insecure session id. Apache::SessionX generates session ids insecurely. The default session id generator in Apache::SessionX::Generate::MD5 returns a MD5 hash seeded with the built-in rand() function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.

In Progress® Telerik® UI for AJAX, versions prior to 2026.1.225, an insufficient entropy vulnerability exists in RadAsyncUpload, where a predictable temporary identifier, based on timestamp and filename, can enable collisions and file content tampering.

Smolder versions through 1.51 for Perl uses insecure rand() function for cryptographic functions. Smolder 1.51 and earlier for Perl uses the rand() function as the default source of entropy, which is not cryptographically secure, for cryptographic functions. Specifically Smolder::DB::Developer uses the Data::Random library which specifically states that it is "Useful mostly for test programs". Data::Random uses the rand() function.

The Popup Builder – Create highly converting, mobile friendly marketing popups. plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 4.4.2. This is due to the plugin generating predictable unsubscribe tokens using deterministic data. This makes it possible for unauthenticated attackers to unsubscribe arbitrary subscribers from mailing lists via brute-forcing the unsubscribe token, granted they know the victim's email address

An insufficient entropy vulnerability was found in glibc. The getrandom and arc4random family of functions may return predictable randomness if these functions are called again after the fork, which happens concurrently with a call to any of these functions.

Concierge::Sessions versions from 0.8.1 before 0.8.5 for Perl generate insecure session ids. The generate_session_id function in Concierge::Sessions::Base defaults to using the uuidgen command to generate a UUID, with a fallback to using Perl's built-in rand function. Neither of these methods are secure, and attackers are able to guess session_ids that can grant them access to systems. Specifically, * There is no warning when uuidgen fails. The software can be quietly using the fallback rand() function with no warnings if the command fails for any reason. * The uuidgen command will generate a time-based UUID if the system does not have a high-quality random number source, because the call does not explicitly specify the --random option. Note that the system time is shared in HTTP responses. * UUIDs are identifiers whose mere possession grants access, as per RFC 9562. * The output of the built-in rand() function is predictable and unsuitable for security applications.

Maypole versions from 2.10 through 2.13 for Perl generates session ids insecurely. The session id is seeded with the system time (which is available from HTTP response headers), a call to the built-in rand() function, and the PID.

The Micca KE700 system relies on a 6-bit portion of an identifier for authentication within rolling codes, providing only 64 possible combinations. This low entropy allows an attacker to perform a brute-force attack against one component of the rolling code. Successful exploitation simplify an attacker to predict the next valid rolling code, granting unauthorized access to the vehicle.

WWW::OAuth 1.000 and earlier for Perl uses the rand() function as the default source of entropy, which is not cryptographically secure, for cryptographic functions.

Fiber is an Express inspired web framework written in Go. Before 2.52.11, on Go versions prior to 1.24, the underlying crypto/rand implementation can return an error if secure randomness cannot be obtained. Because no error is returned by the Fiber v2 UUID functions, application code may unknowingly rely on predictable, repeated, or low-entropy identifiers in security-critical pathways. This is especially impactful because many Fiber v2 middleware components (session middleware, CSRF, rate limiting, request-ID generation, etc.) default to using utils.UUIDv4(). This vulnerability is fixed in 2.52.11.

DPA countermeasures in Silicon Labs' Series 2 devices are not reseeded under certain conditions.  This may allow an attacker to eventually extract secret keys through a DPA attack.

Rapid7 Nexpose versions 6.4.50 and later are vulnerable to an insufficient entropy issue in the CredentialsKeyStorePassword.generateRandomPassword() method. When updating legacy keystore passwords, the application generates a new password with insufficient length (7-12 characters) and a static prefix 'p', resulting in a weak keyspace. An attacker with access to the nsc.ks file can brute-force this password using consumer-grade hardware to decrypt stored credentials.

A weakness in the web interface’s application layer encryption in VX800v v1.0 allows an adjacent attacker to brute force the weak AES key and decrypt intercepted traffic. Successful exploitation requires network proximity but no authentication, and may result in high impact to confidentiality, integrity, and availability of transmitted data.

The anti-theft protection mechanism can be bypassed by attackers due to weak response generation algorithms for the head unit. It is possible to reveal all 32 corresponding responses by sniffing CAN traffic or by pre-calculating the values, which allow to bypass the protection. First identified on Nissan Leaf ZE1 manufactured in 2020.

RustCrypto: Elliptic Curves is general purpose Elliptic Curve Cryptography (ECC) support, including types and traits for representing various elliptic curve forms, scalars, points, and public/secret keys composed thereof. In versions 0.14.0-pre.0 and 0.14.0-rc.0, a critical vulnerability exists in the SM2 Public Key Encryption (PKE) implementation where the ephemeral nonce k is generated with severely reduced entropy. A unit mismatch error causes the nonce generation function to request only 32 bits of randomness instead of the expected 256 bits. This reduces the security of the encryption from a 128-bit level to a trivial 16-bit level, allowing a practical attack to recover the nonce k and decrypt any ciphertext given only the public key and ciphertext. This issue has been patched via commit e4f7778.

Arteco Web Client DVR/NVR contains a session hijacking vulnerability with insufficient session ID complexity that allows remote attackers to bypass authentication. Attackers can brute force session IDs within a specific numeric range to obtain valid sessions and access live camera streams without authorization.

VPN Firewall developed by QNO Technology has a Insufficient Entropy vulnerability, allowing unauthenticated remote attackers to obtain any logged-in user session through brute-force attacks and subsequently log into the system.

coturn is a free open source implementation of TURN and STUN Server. Versions 4.6.2r5 through 4.7.0-r4 have a bad random number generator for nonces and port randomization after refactoring. Additionally, random numbers aren't generated with openssl's RAND_bytes but libc's random() (if it's not running on Windows). When fetching about 50 sequential nonces (i.e., through sending 50 unauthenticated allocations requests) it is possible to completely reconstruct the current state of the random number generator, thereby predicting the next nonce. This allows authentication while spoofing IPs. An attacker can send authenticated messages without ever receiving the responses, including the nonce (requires knowledge of the credentials, which is e.g., often the case in IoT settings). Since the port randomization is deterministic given the pseudorandom seed, an attacker can exactly reconstruct the ports and, hence predict the randomization of the ports. If an attacker allocates a relay port, they know the current port, and they are able to predict the next relay port (at least if it is not used before). Commit 11fc465f4bba70bb0ad8aae17d6c4a63a29917d9 contains a fix.

FreshRSS is a free, self-hostable RSS aggregator. Prior to version 1.28.0, FreshRSS uses cryptographically weak random number generators (mt_rand() and uniqid()) to generate remember-me authentication tokens and challenge-response nonces. This allows attackers to predict valid session tokens, leading to account takeover through persistent session hijacking. The remember-me tokens provide permanent authentication and are the sole credential for "keep me logged in" functionality. This issue has been patched in version 1.28.0.

Use of a weak pseudo-random number generator, which may allow an attacker to read or inject encrypted PowerG packets.

WBCE CMS is a content management system. Versions 1.6.4 and below use function GenerateRandomPassword() to create passwords using PHP's rand(). rand() is not cryptographically secure, which allows password sequences to be predicted or brute-forced. This can lead to user account compromise or privilege escalation if these passwords are used for new accounts or password resets. The vulnerability is fixed in version 1.6.5.

Fiber Utils is a collection of common functions created for Fiber. In versions 2.0.0-rc.3 and below, when the system's cryptographic random number generator (crypto/rand) fails, both functions silently fall back to returning predictable UUID values, including the zero UUID "00000000-0000-0000-0000-000000000000". The vulnerability occurs through two related but distinct failure paths, both ultimately caused by crypto/rand.Read() failures, compromising the security of all Fiber applications using these functions for security-critical operations. This issue is fixed in version 2.0.0-rc.4.

The Litmus platform uses JWT for authentication and authorization, but the secret being used for signing the JWT is only 6 bytes long at its core, which makes it extremely easy to crack.

The KDE Connect verification-code protocol before 2025-04-18 uses only 8 characters and therefore allows brute-force attacks. This affects KDE Connect before 1.33.0 on Android, KDE Connect before 25.04 on desktop, KDE Connect before 0.5 on iOS, Valent before 1.0.0.alpha.47, and GSConnect before 59.

Apache Druid’s Kerberos authenticator uses a weak fallback secret when the `druid.auth.authenticator.kerberos.cookieSignatureSecret` configuration is not explicitly set. In this case, the secret is generated using `ThreadLocalRandom`, which is not a crypto-graphically secure random number generator. This may allow an attacker to predict or brute force the secret used to sign authentication cookies, potentially enabling token forgery or authentication bypass. Additionally, each process generates its own fallback secret, resulting in inconsistent secrets across nodes. This causes authentication failures in distributed or multi-broker deployments, effectively leading to a incorrectly configured clusters. Users are advised to configure a strong `druid.auth.authenticator.kerberos.cookieSignatureSecret` This issue affects Apache Druid: through 34.0.0. Users are recommended to upgrade to version 35.0.0, which fixes the issue making it mandatory to set `druid.auth.authenticator.kerberos.cookieSignatureSecret` when using the Kerberos authenticator. Services will fail to come up if the secret is not set.

The WP 2FA WordPress plugin does not generate backup codes with enough entropy, which could allow attackers to bypass the second factor by brute forcing them

Incorrect Usage of Seeds in Pseudo-Random Number Generator (CWE- 335) vulnerability in the High Sec ELM may allow a sophisticated attacker with physical access, to compromise internal device communications. This issue affects Command Centre Server: 9.30 prior to vCR9.30.251028a (distributed in 9.30.2881 (MR3)), 9.20 prior to vCR9.20.251028a (distributed in 9.20.3265 (MR5)), 9.10 prior to vCR9.10.251028a (distributed in 9.10.4135 (MR8)), all versions of 9.00 and prior.

A vulnerability was identified in the password generation algorithm when accessing the debug-interface. An unauthenticated local attacker with knowledge of the password generation timeframe might be able to brute force the password in a timely manner and thus gain root access to the device if the debug interface is still enabled.

In specific circumstances, due to a weakness in the Pseudo Random Number Generator (PRNG) that is used, it is possible for an attacker to predict the source port and query ID that BIND will use. This issue affects BIND 9 versions 9.16.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.16.8-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.

On Mercku M6a devices through 2.1.0, the authentication system uses predictable session tokens based on timestamps.

Crypt::RandomEncryption for Perl version 0.01 uses insecure rand() function during encryption.

Starch versions 0.14 and earlier generate session ids insecurely. The default session id generator returns a SHA-1 hash seeded with a counter, the epoch time, the built-in rand function, the PID, and internal Perl reference addresses. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.

Apache::AuthAny::Cookie v0.201 or earlier for Perl generates session ids insecurely. Session ids are generated using an MD5 hash of the epoch time and a call to the built-in rand function. The epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.

A deterministic three‑character prefix in the Password Generation component of TYPO3 CMS versions 12.0.0–12.4.36 and 13.0.0–13.4.17 reduces entropy, allowing attackers to carry out brute‑force attacks more quickly.

Due to the lack of randomness in assigning Object Identifiers in the SAP NetWeaver AS JAVA IIOP service, an authenticated attacker with low privileges could predict the identifiers by conducting a brute force search. By leveraging knowledge of several identifiers generated close to the same time, the attacker could determine a desired identifier which could enable them to access limited system information. This poses a low risk to confidentiality without impacting the integrity or availability of the service.

Catalyst::Authentication::Credential::HTTP versions 1.018 and earlier for Perl generate nonces using the Perl Data::UUID library. * Data::UUID does not use a strong cryptographic source for generating UUIDs. * Data::UUID returns v3 UUIDs, which are generated from known information and are unsuitable for security, as per RFC 9562. * The nonces should be generated from a strong cryptographic source, as per RFC 7616.

Thinbus Javascript Secure Remote Password is a browser SRP6a implementation for zero-knowledge password authentication. In versions 2.0.0 and below, a protocol compliance bug causes the client to generate a fixed 252 bits of entropy instead of the intended bit length of the safe prime (defaulted to 2048 bits). The client public value is being generated from a private value that is 4 bits below the specification. This reduces the protocol's designed security margin it is now practically exploitable. The servers full sized 2048 bit random number is used to create the shared session key and password proof. This is fixed in version 2.0.1.

Vision UI is a collection of enterprise-grade, dependency-free modules for modern web projects. In versions 1.4.0 and below, the getSecureRandomInt function in security-kit versions prior to 3.5.0 (packaged in Vision-ui <= 1.4.0) contains a critical cryptographic weakness. Due to a silent 32-bit integer overflow in its internal masking logic, the function fails to produce a uniform distribution of random numbers when the requested range between min and max is larger than 2³². The root cause is the use of a 32-bit bitwise left-shift operation (<<) to generate a bitmask for the rejection sampling algorithm. This causes the mask to be incorrect for any range requiring 32 or more bits of entropy. This issue is fixed in version 1.5.0.

In the OpenSSL compatibility layer implementation, the function RAND_poll() was not behaving as expected and leading to the potential for predictable values returned from RAND_bytes() after fork() is called. This can lead to weak or predictable random numbers generated in applications that are both using RAND_bytes() and doing fork() operations. This only affects applications explicitly calling RAND_bytes() after fork() and does not affect any internal TLS operations. Although RAND_bytes() documentation in OpenSSL calls out not being safe for use with fork() without first calling RAND_poll(), an additional code change was also made in wolfSSL to make RAND_bytes() behave similar to OpenSSL after a fork() call without calling RAND_poll(). Now the Hash-DRBG used gets reseeded after detecting running in a new process. If making use of RAND_bytes() and calling fork() we recommend updating to the latest version of wolfSSL. Thanks to Per Allansson from Appgate for the report.

Catalyst::Plugin::Session before version 0.44 for Perl generates session ids insecurely. The session id is generated from a (usually SHA-1) hash of a simple counter, the epoch time, the built-in rand function, the PID and the current Catalyst context. This information is of low entropy. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.

Authen::DigestMD5 versions 0.01 through 0.02 for Perl generate the cnonce insecurely. The cnonce (client nonce) is generated from an MD5 hash of the PID, the epoch time and the built-in rand function. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. According to RFC 2831, "The cnonce-value is an opaque quoted string value provided by the client and used by both client and server to avoid chosen plaintext attacks, and to provide mutual authentication. The security of the implementation depends on a good choice. It is RECOMMENDED that it contain at least 64 bits of entropy."

Authen::SASL::Perl::DIGEST_MD5 versions 2.04 through 2.1800 for Perl generates the cnonce insecurely. The cnonce (client nonce) is generated from an MD5 hash of the PID, the epoch time and the built-in rand function. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. According to RFC 2831, The cnonce-value is an opaque quoted string value provided by the client and used by both client and server to avoid chosen plaintext attacks, and to provide mutual authentication. The security of the implementation depends on a good choice. It is RECOMMENDED that it contain at least 64 bits of entropy.

Plack-Middleware-Session before version 0.35 for Perl generates session ids insecurely. The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage. Predicable session ids could allow an attacker to gain access to systems.

A CWE-331: Insufficient Entropy vulnerability exists that could cause root password discovery when the password generation algorithm is reverse engineered with access to installation or upgrade artifacts.

A vulnerability classified as problematic was found in D-Link DCS-6517 and DCS-7517 up to 2.02.0. Affected by this vulnerability is the function generate_pass_from_mac of the file /bin/httpd of the component Root Password Generation Handler. The manipulation leads to insufficient entropy. The attack can be launched remotely. The complexity of an attack is rather high. The exploitation appears to be difficult. The exploit has been disclosed to the public and may be used. This vulnerability only affects products that are no longer supported by the maintainer.

Successful exploitation of the vulnerability could allow an unauthenticated attacker to conduct brute force guessing and account takeover as the session cookies are predictable, potentially allowing the attackers to gain root, admin or user access and reset passwords.

Meshtastic is an open source mesh networking solution. In versions from 2.5.0 to before 2.6.11, the flashing procedure of several hardware vendors was resulting in duplicated public/private keys. Additionally, the Meshtastic was failing to properly initialize the internal randomness pool on some platforms, leading to possible low-entropy key generation. When users with an affected key pair sent Direct Messages, those message could be captured and decrypted by an attacker that has compiled the list of compromised keys. This issue has been patched in version 2.6.11 where key generation is delayed til the first time the LoRa region is set, along with warning users when a compromised key is detected. Version 2.6.12 furthers this patch by automatically wiping known compromised keys when found. A workaround to this vulnerability involves users doing a complete device wipe to remove vendor-cloned keys.

Mojolicious::Plugin::CaptchaPNG version 1.05 for Perl uses a weak random number source for generating the captcha. That version uses the built-in rand() function for generating the captcha text as well as image noise, which is insecure.

Mojolicious::Plugin::CSRF 1.03 for Perl uses a weak random number source for generating CSRF tokens. That version of the module generates tokens as an MD5 of the process id, the current time, and a single call to the built-in rand() function.