FacturaScripts has Insecure Parameter Handling: Unauthorized Modification of Immutable 'nick' Field

Description

Summary

The application fails to validate the nick parameter during a POST request to the EditUser controller. Although the UI prevents editing this field, a user can bypass this restriction using a proxy to rename any account (including the Administrator). This leads to Broken Access Control and potential Audit Log Corruption.

Details

The vulnerability exists in the user update logic. When a POST request is sent to /EditUser, the backend processes the nick form-data parameter without checking if it matches the original value or if the user has the privilege to change a unique identifier that is intended to be immutable.

PoC

1. Log in to the dashboard as any user (e.g. admin user).

2. Go to your Profile by clicking your username/avatar in the top right.

3. Open Burp Suite and ensure Intercept is ON.

5. Click the Save button in the UI.

6. In Burp Suite, locate nick in the body:

<img width="1915" height="1013" alt="Screenshot_2026-03-04_05_26_32" src="https://github.com/user-attachments/assets/aea4e6fd-beba-4a47-96da-8b9bd9075681" />

7. Change the value admin to Vulnerable (or any other string).

8. Click Forward in Burp Suite.

The application will log the user out. It is possible to now log back in using the username "Vulnerable" and the original password.

Impact

An attacker can effectively sabotage the system’s audit trail, performing malicious actions and then renaming their account to evade detection or frame other users. This breakdown in accountability facilitates identity impersonation and risks data corruption, as internal references to the original username become orphaned, undermining the overall integrity of the multi-user environment.

Result

Before

<img width="1920" height="996" alt="Screenshot_2026-03-04_05_25_30" src="https://github.com/user-attachments/assets/3b2d34e5-a2b9-4da9-9a56-963fe1a8fd65" />

After

<img width="1920" height="955" alt="Screenshot_2026-03-04_05_27_00" src="https://github.com/user-attachments/assets/af1de0ef-2b55-4d29-9557-29ee26a3775a" />

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-04-28 22:39:01 UTC
Updated
2026-05-07 18:46:58 UTC
GitHub reviewed
2026-04-28 22:39:01 UTC
NVD published
2026-05-05 20:16:35 UTC

EPSS Score

Score Percentile
0.01% 2.58%

CVSS Scores

Base score Version Severity Vector
4.3 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
5.3 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:L)
Low privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:L)
Limited integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:X)
Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.

Identifiers

CWEs

CWE id Name
CWE-284 Improper Access Control
CWE-472 External Control of Assumed-Immutable Web Parameter

Credits

  • TurkiOS (reporter)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
composer facturascripts/facturascripts <= 2024.92.x-dev

References

cvelogic Threat Intelligence