8.1 CVE-2026-25726

Enriched by CISA
 

Cloudreve is a self-hosted file management and sharing system. Prior to version 4.13.0, the application uses the weak pseudo-random number generator math/rand seeded with time.Now().UnixNano() to generate critical security secrets, including the secret_key, and hash_id_salt. These secrets are generated upon first startup and persisted in the database. An attacker can exploit this by obtaining the administrator's account creation time (via public API endpoints) to narrow the search window for the PRNG seed, and use known hashid to validate the seed. By brute-forcing the seed (demonstrated to take <3 hours on general consumer PC), an attacker can predict the secret_key. This allows them to forge valid JSON Web Tokens (JWTs) for any user, including administrators, leading to full account takeover and privilege escalation. This issue has been patched in version 4.13.0.
https://nvd.nist.gov/vuln/detail/CVE-2026-25726

Categories

CWE-338 : Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong. Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.) Use functions or hardware which use a hardware-based random number generation for all crypto. This is the recommended solution. Use CyptGenRandom on Windows, or hw_rand() on Linux. PHP framework uses mt_rand() function (Marsenne Twister) when generating tokens Crypto product uses rand() library function to generate a recovery key, making it easier to conduct brute force attacks. Random number generator can repeatedly generate the same value. Web application generates predictable session IDs, allowing session hijacking. SSL library uses a weak random number generator that only generates 65,536 unique keys.

References


 

AFFECTED (from MITRE)

Vendor Product Versions
cloudreve cloudreve
  • < 4.13.0 [affected]
© 2022 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.

CPE

cpe start end

REMEDIATION


EXPLOITS

Exploit-db.com

id description date
No known exploits

POC Github

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No known exploits

Other Nist (github, ...)

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No known exploits

CAPEC

Common Attack Pattern Enumerations and Classifications

id description severity
No entry