CVE-2026-61500: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in rejetto hfs
Rejetto HFS versions 3.0.0 through 3.2.0 use a cryptographically weak pseudo-random number generator (Math.random()) to derive session-cookie signing keys and disclose outputs of this generator to unauthenticated clients during login. This weakness allows a remote attacker to reconstruct the generator's state, recover the signing key, and forge valid administrator session cookies. Successful exploitation leads to full administrative access and remote code execution via the server_code configuration feature.
AI Analysis
Technical Summary
The vulnerability in Rejetto HFS 3.0.0 through 3.2.0 arises from using the non-cryptographic Math.random() function to generate session-cookie signing keys. Additionally, outputs from this generator are exposed to unauthenticated clients during login. An attacker can collect a small number of these outputs, reconstruct the internal state of the PRNG, recover the signing key, and forge administrator session cookies. This enables full administrative access and remote code execution through the server_code feature. The CVSS 4.0 score is 9.3, indicating a critical severity with network attack vector, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability.
Potential Impact
An attacker can remotely gain full administrative access to the affected Rejetto HFS servers without authentication. This includes the ability to execute arbitrary code remotely via the server_code configuration feature, potentially compromising the entire system running the vulnerable software.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is indicated in the available data. Until a patch is released, restrict access to the affected HFS versions and monitor for suspicious activity related to session cookie forgery.
CVE-2026-61500: Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG) in rejetto hfs
Description
Rejetto HFS versions 3.0.0 through 3.2.0 use a cryptographically weak pseudo-random number generator (Math.random()) to derive session-cookie signing keys and disclose outputs of this generator to unauthenticated clients during login. This weakness allows a remote attacker to reconstruct the generator's state, recover the signing key, and forge valid administrator session cookies. Successful exploitation leads to full administrative access and remote code execution via the server_code configuration feature.
CVSS v4.0
Score 9.3critical
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Rejetto HFS 3.0.0 through 3.2.0 arises from using the non-cryptographic Math.random() function to generate session-cookie signing keys. Additionally, outputs from this generator are exposed to unauthenticated clients during login. An attacker can collect a small number of these outputs, reconstruct the internal state of the PRNG, recover the signing key, and forge administrator session cookies. This enables full administrative access and remote code execution through the server_code feature. The CVSS 4.0 score is 9.3, indicating a critical severity with network attack vector, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability.
Potential Impact
An attacker can remotely gain full administrative access to the affected Rejetto HFS servers without authentication. This includes the ability to execute arbitrary code remotely via the server_code configuration feature, potentially compromising the entire system running the vulnerable software.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is indicated in the available data. Until a patch is released, restrict access to the affected HFS versions and monitor for suspicious activity related to session cookie forgery.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-07-10T15:43:36.625Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a55288d68715ace4399fcd3
Added to database: 07/13/2026, 18:03:57 UTC
Last enriched: 07/13/2026, 18:17:34 UTC
Last updated: 07/14/2026, 03:33:27 UTC
Views: 10
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