CVE-2021-45268
A Cross Site Request Forgery (CSRF) vulnerability exists in Backdrop CMS 1.20, which allows Remote Attackers to gain Remote Code Execution (RCE) on the Hosting Webserver via uploading a maliciously add-on with crafted PHP file.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.82%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A Cross Site Request Forgery (CSRF) vulnerability exists in Backdrop CMS 1.20, which allows Remote Attackers to gain Remote Code Execution (RCE) on the Hosting Webserver via uploading a maliciously add-on with crafted PHP file. NOTE: the vendor disputes this because the attack requires a session cookie of a high-privileged authenticated user who is entitled to install arbitrary add-ons
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 1.82% probability · 79th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-352
- Affected
- backdropcms/backdrop
- Source
- cve@mitre.org
EPSS 1.8% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/V1n1v131r4/CSRF-to-RCE-on-Backdrop-CMSExploit, Third Party Advisory
- https://www.exploit-db.com/exploits/50323Third Party Advisory, VDB Entry
- https://github.com/V1n1v131r4/CSRF-to-RCE-on-Backdrop-CMSExploit, Third Party Advisory
- https://www.exploit-db.com/exploits/50323Third Party Advisory, VDB Entry
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.