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Sakai kernel-impl: predictable PRNG used to generate server‑side encryption key in EncryptionUtilityServiceImpl

Low severity GitHub Reviewed Published Oct 22, 2025 in sakaiproject/sakai • Updated Oct 22, 2025

Package

maven org.sakaiproject.kernel:sakai-kernel-impl (Maven)

Affected versions

<= 23.3

Patched versions

None

Description

Impact

EncryptionUtilityServiceImpl initialized an AES256TextEncryptor password (serverSecretKey) using RandomStringUtils with the default java.util.Random. java.util.Random is a non‑cryptographic PRNG and can be predicted from limited state/seed information (e.g., start time window), substantially reducing the effective search space of the generated key. An attacker who can obtain ciphertexts (e.g., exported or at‑rest strings protected by this service) and approximate the PRNG seed can feasibly reconstruct the serverSecretKey and decrypt affected data.

Patches

SAK-49866 is patched in Sakai 23.5, 25.0, and trunk.

Credits

  • Reported by Suraj Gangwar.
  • Patched by Sam Ottenhoff (Longsight).

References

@ottenhoff ottenhoff published to sakaiproject/sakai Oct 22, 2025
Published to the GitHub Advisory Database Oct 22, 2025
Reviewed Oct 22, 2025
Last updated Oct 22, 2025

Severity

Low

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N

EPSS score

Weaknesses

Predictable Seed in Pseudo-Random Number Generator (PRNG)

A Pseudo-Random Number Generator (PRNG) is initialized from a predictable seed, such as the process ID or system time. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-gr7h-xw4f-wh86

Source code

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