Cyber Resilience

CVE-2025-25205

Auth Bypass in Audiobookshelf 2.17.0 – 2.19.1

Public PoCAuth BypassDoS
Published
12 February 2025
Modified
03 July 2025
Patch / advisory
CVSS Score v3.1 8.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
EPSS Score 0.042 90th percentile
Risk Priority 67 floored blend · peak EPSS

Summary

CVE-2025-25205 is a high-severity Exposure of Sensitive Information Through Data Queries (CWE-202) vulnerability in Audiobookshelf Audiobookshelf. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Exhaustion Flood (T1499.001); ranked in the top 10% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-23 (Data Mining Protection) and IA-2 (Identification and Authentication (Organizational Users)) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

Audiobookshelf, a self-hosted audiobook and podcast server, is affected by CVE-2025-25205 in versions starting from 2.17.0 and prior to 2.19.1. The vulnerability arises from a flaw in the authentication bypass logic, where unauthenticated requests can match certain unanchored regex patterns in the URL. This issue, published on 2025-02-12, carries a CVSS v3.1 base score of 8.2 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H) and maps to CWEs 202 (sensitive data exposure), 287 (improper authentication), and 400 (uncontrolled resource consumption).

Unauthenticated attackers with network access can exploit this vulnerability by crafting malicious URLs containing substrings like "/api/items/1/cover" within a query parameter, such as ?r=/api/items/1/cover. This enables partial bypass of authentication, potentially disclosing otherwise protected data. In certain routes, the flaw can also cause server crashes if downstream code assumes an authenticated user object is present, leading to denial of service.

The vulnerability is addressed in Audiobookshelf version 2.19.1. Mitigation details are outlined in the GitHub security advisory (GHSA-pg8v-5jcv-wrvw), pull request #3584, and commits bf8407274e3ee300af1927ee660d078a7a801e1c and ec6537656925a43871b07cfee12c9f383844d224, with the affected authentication logic visible in server/Auth.js lines 17-41.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Audiobookshelf is a self-hosted audiobook and podcast server. Starting in version 2.17.0 and prior to version 2.19.1, a flaw in the authentication bypass logic allows unauthenticated requests to match certain unanchored regex patterns in the URL. Attackers can craft URLs…

more

containing substrings like "/api/items/1/cover" in a query parameter (?r=/api/items/1/cover) to partially bypass authentication or trigger server crashes under certain routes. This could lead to information disclosure of otherwise protected data and, in some cases, a complete denial of service (server crash) if downstream code expects an authenticated user object. Version 2.19.1 contains a patch for the issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499.001 OS Exhaustion Flood Impact
Adversaries may launch a denial of service (DoS) attack targeting an endpoint's operating system (OS).
T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1213 Data from Information Repositories Collection
Adversaries may leverage information repositories to mine valuable information.
T1213.006 Databases Collection
Adversaries may leverage databases to mine valuable information.
T1498 Network Denial of Service Impact
Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-27963Same product: Audiobookshelf Audiobookshelf
CVE-2025-46338Same product: Audiobookshelf Audiobookshelf
CVE-2024-35236Same product: Audiobookshelf Audiobookshelf
CVE-2023-47624Same product: Audiobookshelf Audiobookshelf
CVE-2023-51665Same product: Audiobookshelf Audiobookshelf
CVE-2024-43797Same product: Audiobookshelf Audiobookshelf
CVE-2023-51697Same product: Audiobookshelf Audiobookshelf
CVE-2025-57800Same product: Audiobookshelf Audiobookshelf
CVE-2023-47619Same product: Audiobookshelf Audiobookshelf
CVE-2026-27973Same product: Audiobookshelf Audiobookshelf

Affected Assets

audiobookshelf
audiobookshelf
2.17.0 — 2.19.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 8 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.4.4
  • V6.5.4
  • V6.5.5
  • V6.5.7

Mitigating Controls (NIST 800-53 r5) AI

Mandates unique identification and authentication of organizational users before access, directly stopping improper authentication.

Requires unique identification and authentication of devices before establishing connections, preventing unauthenticated device claims.

Mandates unique identification and authentication of non-organizational users, directly addressing the weakness for external actors.

AC-23 directly requires mechanisms to protect against unauthorized data mining and inference from statistical queries that would expose sensitive information.

Manages authenticators with verification and secure distribution, reducing opportunities for improper authentication.

SC-5 directly limits the effects of resource-exhaustion events that constitute uncontrolled consumption.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 mostly match
prevents

PR.AA-03 directly enforces authentication mechanisms that eliminate most improper-authentication defects, yet CWE-287 spans additional vectors (missing checks, flawed protocols, session handling) that one control does not fully close.

PR.AA-04 mostly match
prevents

PR.AA-04 directly enables verification of identity assertions (mostly preventing CWE-287 in that scope) yet leaves many other authentication failure modes unaddressed (only partial prevention overall).

PR.AA-05 mostly match
prevents

Least-privilege query permissions directly limit the data an attacker can request or infer.

PR.IR-04 mostly match
prevents

Explicitly requires monitoring and maintaining resource capacity, directly addressing uncontrolled consumption to preserve availability.

DE.CM-03 partial match
prevents

Behavior analytics on query activity can detect inference attempts but does not prevent exposure at query time.

DE.CM-09 partial match
prevents

Continuous monitoring of computing resources can detect resource exhaustion but does not itself enforce allocation limits.

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.

prevents

Requiring authentication methods whose strength matches the sensitivity of the data and mandating multi-factor authentication directly blocks attempts to access resources without proving identity.

prevents

Access control limits who can run queries that could expose sensitive information via inference.

prevents

Verifying user identity before issuing replacement credentials and forcing changes after compromise reduces the likelihood that authentication bypass can be achieved through stolen or weak credentials.

prevents

Granular access rights reduce the ability of users to craft inference queries.

prevents

Data masking prevents inference by obscuring sensitive values returned in query results.

finds

Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (1 rule)
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-287
RHEL 7 (3 rules)
  • V-204425 The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not allow authentication using an empty password. prevents CWE-287
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-287
  • V-204424 The Red Hat Enterprise Linux operating system must not allow accounts configured with blank or null passwords. prevents CWE-287
RHEL 8 (1 rule)
  • V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-287
Ubuntu 22.04 (1 rule)
  • V-260470 Ubuntu 22.04 LTS, when booted, must require authentication upon booting into single-user and maintenance modes. prevents CWE-287
Ubuntu 24.04 (2 rules)
  • V-270675 Ubuntu 24.04 LTS when booted must require authentication upon booting into single-user and maintenance modes. prevents CWE-287
  • V-270714 Ubuntu 24.04 LTS must not allow accounts configured in Pluggable Authentication Modules (PAM) with blank or null passwords. prevents CWE-287

References