Description
The Crayons plugin for SPIP before 3.5.0 contains a missing authorization vulnerability that allows unauthenticated attackers to modify arbitrary editable object fields by omitting the secu_ anti-forgery parameter in crayons_store.php, causing the authorization dispatcher to resolve an unconditionally-true handler instead of the proper modification check. Attackers can chain this flaw to write a malicious .html skeleton file, disclose sensitive configuration files containing the site secret, and forge a signed ajax context to execute the uploaded skeleton, achieving arbitrary PHP code execution as the web-server user.
References3
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 4.0
-
9.3
CRITICAL
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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 - EPSS — exploit probability
- 1% percentile: 48 · as of 10 November 2026
- CWE
- CWE-862
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.