SPIP 3.1 before 3.1.10 and 3.2 before 3.2.4 allows authenticated visitors to execute arbitrary code on the host server because var_memotri is mishandled.
https://www.debian.org/security/2019/dsa-4429
https://usn.ubuntu.com/4536-1/
https://github.com/spip/SPIP/compare/1e3872c...9861a47
https://github.com/spip/SPIP/commit/824d17f424bf77d17af89c18c3dc807a3199567e
https://github.com/spip/SPIP/commit/3ef87c525bc0768c926646f999a54222b37b5d36
https://blog.spip.net/Mise-a-jour-CRITIQUE-de-securite-Sortie-de-SPIP-3-1-10-et-SPIP-3-2-4.html