Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-42442 is a high-severity Improper Authentication (CWE-287) vulnerability in Fit2Cloud Jumpserver. Its CVSS base score is 8.2 (High).
Operationally, ranked in the top 0.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
JumpServer, an open source bastion host and operations and maintenance audit platform, contains an authentication bypass in versions 3.0.0 through 3.5.4 and 3.6.3. The flaw resides in the session replay download path and stems from a misconfigured permission check on the /api/v1/terminal/sessions/ endpoint, where the RBACPermission and IsSessionAssignee classes are combined with a logical OR, allowing any matching permission to grant access. Session recordings stored in S3, OSS, or similar cloud object storage are unaffected.
An unauthenticated attacker with network access to the JumpServer instance can issue requests to the vulnerable API and retrieve session replays. Successful exploitation yields unauthorized disclosure of recorded administrative sessions and can also permit modification or disruption of replay data, consistent with the CVSS 8.2 rating that reflects network-exploitable integrity and availability impact without credentials or user interaction.
The project’s security advisory and subsequent commits (merged in 3.5.5 and 3.6.4) correct the permission classes so that the same endpoint now returns HTTP 401 for anonymous callers. Administrators are advised to upgrade promptly and verify the change by confirming that requests to /api/v1/terminal/sessions/?limit=1 are rejected when no authentication token is supplied. The EPSS score has remained at its observed peak of 0.8817 since disclosure.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-46892
Vulnerability Data
JumpServer is an open source bastion host and a professional operation and maintenance security audit system. Starting in version 3.0.0 and prior to versions 3.5.5 and 3.6.4, session replays can download without authentication. Session replays stored in S3, OSS, or…
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other cloud storage are not affected. The api `/api/v1/terminal/sessions/` permission control is broken and can be accessed anonymously. SessionViewSet permission classes set to `[RBACPermission | IsSessionAssignee]`, relation is or, so any permission matched will be allowed. Versions 3.5.5 and 3.6.4 have a fix. After upgrading, visit the api `$HOST/api/v1/terminal/sessions/?limit=1`. The expected http response code is 401 (`not_authenticated`).
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Detects unauthorized successful logons resulting from improper authentication implementations.
Documented procedures ensure personnel are trained on authentication mechanisms, tangibly lowering the risk of improper authentication being exploited.
Security awareness training instructs users on secure authentication practices and avoiding credential compromise.
Training on authentication mechanisms and best practices decreases the occurrence of improper authentication.
Non-repudiation requires strong authentication mechanisms to irrefutably attribute performed actions to specific individuals or processes.
Session content review can reveal authentication bypasses or failures in session establishment.
Review of authentication-related audit records can detect improper authentication mechanisms or bypasses.
Assessments check authentication mechanisms for correct implementation and effectiveness, reducing successful authentication bypass attempts.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Mandating segregated approval and oversight for non-human identities reduces the chance that weak or orphaned credentials can be exploited for unauthorized authentication.
A.5.17 directly mandates generation of non-guessable unique secrets, secure transmission, immediate change of defaults/temporary creds, strong password enforcement, no-reuse, and compromise response, which stops most improper-authentication exploits at source; the bounded remainder is non-password authentication methods and sufficiency-of-proof cases (e.g. IA-2/IA-5 enhancements) left to other controls.
Security requirements specified early and verified through testing drive the consistent implementation of authentication mechanisms, decreasing the likelihood that authentication steps are omitted or incorrectly applied.
A.8.26 explicitly requires identifying and addressing authentication-related requirements (including level of trust in identity via 8.5 and 5.17) as part of application development or acquisition, which prevents a slice of CWE-287 but leaves the dominant sufficiency-of-proof aspects (IA-2/IA-5) and many implementation defects untouched.
A.8.27 mandates security-by-design principles (least privilege, default-deny, never-trust/always-verify, MFA, end-to-end encryption of requests, distrust-external-input, secure session control, and explicit authentication/authorization in every layer), which directly stops most improper-authentication flaws from being exploitable; the bounded remainder is insufficient-proof cases that live only in the strength or correctness of the credential itself (IA-5/IA-2 territory).
A.8.5 directly mandates appropriate-strength authentication techniques, MFA for critical systems, protected log-on procedures, brute-force resistance, no cleartext passwords/transmission, and session controls that stop exploitation of insufficient proof of identity; the bounded remainder is cases where the chosen technique itself is flawed or insufficiently implemented (e.g. weak biometrics without fallback).
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.