Security readout for executives and security teams
Plain-English summary
Calibre-web 0.6.0 through 0.6.13 can let an attacker abuse a logged-in user's browser to create an attacker-controlled admin account. The business risk is full application takeover, including access to hosted library data and administrative functions.
Executive priority
Treat this as a prompt remediation item for any internet-accessible or broadly reachable Calibre-web instance. The vulnerability can lead to administrative takeover, but available sources do not establish active exploitation.
Technical view
The issue is a CSRF weakness in Calibre-web user administration. With user interaction from an authenticated victim, a network attacker can cause creation of a new role/user with admin privileges and controlled credentials. CVSS 3.1 is 8.8 high, mapped to CWE-352.
Likely exposure
Organizations running Calibre-web versions 0.6.0 to 0.6.13 are potentially exposed, especially if the web interface is reachable by users who stay authenticated. Exposure is lower where access is tightly restricted and administrators do not browse untrusted links while logged in.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. Exploitation requires social engineering or another path to make an authenticated Calibre-web user click a crafted link, then relies on missing CSRF protection to create privileged access.
Researcher notes
Avoid assuming unauthenticated direct account creation. The documented attack depends on CSRF against an authenticated user and user interaction. Public sources identify the vulnerable range and a related upstream commit, but the bundle does not explicitly name a fixed release.
Mitigation direction
- Identify all Calibre-web deployments and record their versions.
- Upgrade or apply the vendor fix according to Calibre-web guidance.
- Restrict Calibre-web access to trusted networks or VPN users.
- Require administrators to log out when not actively managing the service.
- Review existing Calibre-web users for unexpected admin accounts.
Validation and detection
- Confirm deployed Calibre-web versions are not 0.6.0 through 0.6.13.
- Check whether user administration requests include effective CSRF protections.
- Audit users and roles for recently created privileged accounts.
- Review access logs for suspicious account creation activity.
- Verify any upgrade or fix in a staging environment before production rollout.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-352: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-25965 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/janeczku/calibre-web/commit/50919d47212066c75f03ee7a5332ecf2d584b98eCVE reference · x_refsource_MISC
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25965CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.