Generation of Predictable Numbers or Identifiers

Dancer2 versions through 2.1.0 for Perl generate insecure session ids when required CSPRNG modules are unavailable. Dancer2::Core::Role::SessionFactory::generate_id silently falls back to a built-in rand-derived session id unless both Math::Random::ISAAC::XS and Crypt::URandom are available. The fallback session id is generated from a SHA-1 hash of a call to the built-in rand function, the absolute path of the Dancer2::Core::Role::SessionFactory module, an internal counter, the process id, the module instance memory address, and a shuffled string of characters (using the List::Util::shuffle function, which also uses the built-in rand function). These are all low-entropy and easily guessed sources. The built-in rand() function is seeded with 32-bits and considered unsuitable for security applications. Predictable session ids could allow an attacker to gain access to systems.Show less

An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2. URLAUTH token forgery can occur via a missing mboxkey. If an attacker knew a folder name on the victim's account for which the victim had never issued an auth URL, they could forge a working URLAUTH token by computing an HMAC-SHA1 value with a predictable key, giving them read access to the mailbox. (URLAUTH is an obscure feature, meaning that the odds of any user actually being susceptible to this attack are very low. Perhaps no public clients use URLAUTH.)Show less

CGI::Session::ID::md5 versions before 4.49 for Perl generate predictable session ids from low-entropy sources. The generate_id method builds the session id from a MD5 digest of the process id, the epoch time, and the built-in rand() function. All three are predictable, low-entropy sources: the PID is drawn from a small range, the epoch time can be guessed or read from the HTTP Date header, and Perl's rand() is unsuitable for security purposes because it is predictable and reversible. An attacker who predicts a session id can impersonate the corresponding session and bypass authentication.Show less

Setracker2 Android Companion App com.tgelec.setracker versions 3.1.5 and prior have a predictable registration ID derived from IMEI. The enrollment system lacks additional authentication before assignment. If an attacker is able to obtain the registration ID, they would be able to arbitrarily enroll watches belonging to other users.Show less

In ManageEngine ADSelfService Plus, RecoveryManager Plus, M365 Manager Plus, and ADAudit Plus, the SSO tickets generated to authenticate that session could be predicted by an unauthenticated user, leading to account takeover.Show less

Mojolicious::Plugin::Web::Auth::OAuth2 versions through 0.17 for Perl have an insecure default state parameter. When no state generator is specified in the constructor, the module defaults to using a SHA-1 hash of predictable and low-entropy sources, including the epoch time (which is leaked via the HTTP Date header) and a call to Perl's built-in rand function. A predictable state allows an attacker to hijack another user's session through cross site request forgery (CSRF).Show less

Mojolicious::Sessions::Storable versions through 0.05 for Perl generate session ids insecurely. The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, the heap address of an anonymous hash, and the PID. These are predictable or low-entropy sources that are unsuitable for security purposes.Show less

Naxclow device identifiers use fixed manufacturing prefixes combined with sequential counters, producing a fully predictable and enumerable identifier space. Because the platform also exposes an endpoint that reveals the current identifier high-water mark, the active fleet can be enumerated.Show less

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's DNS resolver uses a predictable PRNG for generating DNS transaction IDs and defaults to a static UDP source port. This combination reduces the entropy of DNS queries, enabling DNS Cache Poisoning (Kaminsky attack). Versions 4.1.135.Final and 4.2.15.Final patch the issue.Show less

Apache::Session::Generate::SHA256 versions before 1.3.19 for Perl create insecure session ids. Apache::Session::Generate::SHA256 generated session ids insecurely. The default session id generator returns a SHA-256 hash of the built-in rand() function, the epoch time, and the PID, that is hashed again. These are predictable, low-entropy sources. Predicable session ids could allow an attacker to gain access to systems. Note that version 1.3.19 has a fallback without warning to use insecure session generation method if the call to Crypt::URandom::urandom fails. However, this is unlikely as Crypt::URandom is a hardcoded requirement of the module. This issue is similar to CVE-2025-40931 for Apache::Session::Generate::MD5.Show less

WebDyne::Session versions through 2.075 for Perl generates the session id insecurely. The session handler generates the session id from an MD5 hash seeded with a call to the built-in rand() function. The rand function is passed a maximum value based on the process id, the epoch time and the reference address of the object, but this information will have no effect on the overall quality of the seed of the message digest. The rand function is seeded by 32-bits and is predictable. It is considered unsuitable for cryptographic purposes. Predictable session ids could allow an attacker to gain access to systems. Note that WebDyne::Session versions 1.042 and earlier appear to be in separate distributions from WebDyne.Show less

Apache::Session::Generate::ModUniqueId versions from 1.54 through 1.94 for Perl session ids are insecure. Apache::Session::Generate::ModUniqueId (added in version 1.54) uses the value of the UNIQUE_ID environment variable for the session id. The UNIQUE_ID variable is set by the Apache mod_unique_id plugin, which generates unique ids for the request. The id is based on the IPv4 address, the process id, the epoch time, a 16-bit counter and a thread index, with no obfuscation. The server IP is often available to the public, and if not available, can be guessed from previous session ids being issued. The process ids may also be guessed from previous session ids. The timestamp is easily guessed (and leaked in the HTTP Date response header). The purpose of mod_unique_id is to assign a unique id to requests so that events can be correlated in different logs. The id is not designed, nor is it suitable for security purposes.Show less

Dancer::Session::Abstract versions through 1.3522 for Perl generates session ids insecurely. The session id is generated from summing the character codepoints of the absolute pathname with the process id, the epoch time and calls to the built-in rand() function to return a number between 0 and 999-billion, and concatenating that result three times. The path name might be known or guessed by an attacker, especially for applications known to be written using Dancer with standard installation locations. The epoch time can be guessed by an attacker, and may be leaked in the HTTP header. The process id comes from a small set of numbers, and workers may have sequential process ids. The built-in rand() function is seeded with 32-bits and is considered unsuitable for security applications. Predictable session ids could allow an attacker to gain access to systems.Show less

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, attachment download tokens are generated using a weak and predictable formula: `md5(APP_KEY + attachment_id + size)`. Since attachment_id is sequential and size can be brute-forced in a small range, an unauthenticated attacker can forge valid tokens and download any private attachment without credentials. Version 1.8.213 fixes the issue.Show less

Solstice::Session versions through 1440 for Perl generates session ids insecurely. The _generateSessionID method returns an MD5 digest seeded by the epoch time, a random hash reference, a call to the built-in rand() function and the process id. The same method is used in the _generateID method in Solstice::Subsession, which is part of the same distribution. The epoch time may be guessed, if it is not leaked in the HTTP Date header. Stringified hash refences will contain predictable content. The built-in rand() function is seeded by 16-bits and is unsuitable for security purposes. The process id comes from a small set of numbers. Predictable session ids could allow an attacker to gain access to systems.Show less

Ado::Sessions versions through 0.935 for Perl generates insecure session ids. The session id is generated from 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. Note that Ado is no longer maintained, and has been removed from the CPAN index. It is still available on BackPAN.Show less

Amon2::Plugin::Web::CSRFDefender versions from 7.00 through 7.03 for Perl generate an insecure session id. The generate_session_id function will attempt to read bytes from the /dev/urandom device, but if that is unavailable then it generates bytes using SHA-1 hash seeded with the built-in rand() function, the PID, and the high resolution epoch time. 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. Amon2::Plugin::Web::CSRFDefender versions before 7.00 were part of Amon2, which was vulnerable to insecure session ids due to CVE-2025-15604. Note that the author has deprecated this module.Show less

Generation of Predictable Numbers or Identifiers vulnerability in Erlang/OTP kernel (inet_res, inet_db modules) allows DNS Cache Poisoning. The built-in DNS resolver (inet_res) uses a sequential, process-global 16-bit transaction ID for UDP queries and does not implement source port randomization. Response validation relies almost entirely on this ID, making DNS cache poisoning practical for an attacker who can observe one query or predict the next ID. This conflicts with RFC 5452 recommendations for mitigating forged DNS answers. inet_res is intended for use in trusted network environments and with trusted recursive resolvers. Earlier documentation did not clearly state this deployment assumption, which could lead users to deploy the resolver in environments where spoofed DNS responses are possible. This vulnerability is associated with program files lib/kernel/src/inet_db.erl and lib/kernel/src/inet_res.erl. This issue affects OTP from OTP 17.0 before OTP 28.4.2, OTP 27.3.4.10 and OTP 26.2.5.19, corresponding to kernel from 3.0 before 10.6.2, 10.2.7.4 and 9.2.4.11.Show less

HTTP::Session versions before 0.54 for Perl defaults to using insecurely generated session ids. HTTP::Session defaults to using HTTP::Session::ID::SHA1 to generate session ids using a SHA-1 hash seeded with the built-in rand function, the high resolution 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. The distribution includes HTTP::session::ID::MD5 which contains a similar flaw, but uses the MD5 hash instead.Show less