CVE-2021-3730Network attack vector

Budget-record deletion via state-changing GET request

Published Aug 23, 2021 · Updated Aug 3, 2024

CSRF in Firefly III 5.5.13 and earlier allows remote attackers to delete an authenticated user's available-budget records. The available-budget deletion route accepts a state-changing GET request, so a crafted link reaches destroyAvailableBudget without a CSRF token. Exploitation requires an authenticated user to open the link and results in deletion of that user's selected available-budget record.

CVSS severity6.5
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSRF in Firefly III 5.5.13 and earlier allows remote attackers to delete an authenticated user's available-budget records. The available-budget deletion route accepts a state-changing GET request, so a crafted link reaches destroyAvailableBudget without a CSRF token. Exploitation requires an authenticated user to open the link and results in deletion of that user's selected available-budget record.

The record

CVE
CVE-2021-3730
Published
Aug 23, 2021
Updated
Aug 3, 2024
Vendor
Firefly III
Product
Firefly III
Classifications
CWE-352, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 23, 2021CVE 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 <=5.5.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Firefly III · Firefly IIIversion=unspecified <=5.5.13

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
4.3NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
6.5huntr.dev CNACVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 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)
T1204.001Malicious Link

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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