CVE-2021-4164Network attack vector

State-changing action execution via unsafe GET routes

Published Jan 17, 2022 · Updated Aug 3, 2024

CSRF in Calibre-Web before 0.6.15 allows remote attackers to trigger state-changing actions through an authenticated user's browser. The shutdown, password-reset, book, shelf, Kobo-token, full-sync, and LDAP-import routes accepted state-changing GET requests, allowing an external page to invoke them with the victim's session. Exploitation requires an authenticated user to visit attacker-controlled content; effects depend on that user's privileges and include deletion, credential or token changes, synchronization changes, and service shutdown.

CVSS severity7.6
High
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSRF in Calibre-Web before 0.6.15 allows remote attackers to trigger state-changing actions through an authenticated user's browser. The shutdown, password-reset, book, shelf, Kobo-token, full-sync, and LDAP-import routes accepted state-changing GET requests, allowing an external page to invoke them with the victim's session. Exploitation requires an authenticated user to visit attacker-controlled content; effects depend on that user's privileges and include deletion, credential or token changes, synchronization changes, and service shutdown.

The record

CVE
CVE-2021-4164
Published
Jan 17, 2022
Updated
Aug 3, 2024
Vendor
Calibre-Web
Product
Calibre-Web
Classifications
CWE-352
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 17, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <0.6.15

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Calibre-Web · Calibre-Webversion=unspecified <0.6.15

Published CVSS scores

7.6GitHub Advisory DatabaseCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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