Backup Guard <= 1.5.9 - Authenticated Arbitrary File Upload
Strategic Overview
- Status
- Patched in 1.6.0
- Affected Plugin
- JetBackup – Backup, Restore & Migrate
- Affected Version
<= 1.5.9- CVSS
- 7.2High
- Weakness type
- CWE-434 · Unrestricted Upload of File with Dangerous Type
- CVE
CVE-2021-24155
At a glance
CVE-2021-24155 is a high-severity Unrestricted Upload of File with Dangerous Type vulnerability in the JetBackup WordPress plugin, affecting versions <= 1.5.9. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account. The issue is fixed in version 1.6.0; sites on affected versions should update now. Disclosed February 2021, reported by Nguyen Van Khanh.
Vulnerability Overview
The WordPress Backup and Migrate Plugin – Backup Guard WordPress plugin before 1.6.0 did not ensure that the imported files are of the SGBP format and extension, allowing high privilege users (admin+) to upload arbitrary files, including PHP ones, leading to RCE.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-434: Unrestricted Upload of File with Dangerous Type
Reaching this weakness in JetBackup <= 1.5.9 takes any authenticated account. An unrestricted file upload lets a caller store a file whose type or destination the application does not properly constrain.
If an uploaded file lands anywhere the server will execute, the flaw becomes remote code execution and the site should be treated as fully compromised. For JetBackup the fix is 1.6.0: builds <= 1.5.9 are affected, anything from 1.6.0 onward is not.
Remediation
Update to version 1.6.0, or a newer patched version
How does WordSec protect against this?
The attempt arrives as an ordinary request to JetBackup: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: JetBackup 1.6.0 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
Related records
Same weakness class
Other vulnerabilities in JetBackup – Backup, Restore & Migrate
- 9.8CVE-2023-7165: JetBackup <= 2.0.9.7 Sensitive Information Exposure
CVE-2023-7165 - 8.8CVE-2020-36669: JetBackup CSRF to Arbitrary File Upload
CVE-2020-36669 - 6.3CVE-2026-19453: JetBackup Privilege Escalation
CVE-2026-19453 - 6.1CVE-2017-10837: BackupGuard <= 1.1.46 Reflected Cross-Site Scripting
CVE-2017-10837 - 6.1CVE-2017-18488: Backup Guard <= 1.1.46 Cross-Site Scripting
CVE-2017-18488 - 5.5CVE-2022-34148: Backup Guard <= 1.6.9 Stored Cross-Site Scripting
CVE-2022-34148 - 5.4CVE-2020-36667: JetBackup Unauthorized Backup Location Change
CVE-2020-36667 - 4.9CVE-2026-19454: JetBackup Backup Download
CVE-2026-19454
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C