Post By Email <= 1.0.4b - Unauthenticated Arbitrary File Upload via Email Attachments
Strategic Overview
- Status
- Unpatched
- Affected Plugin
- Post By Email
- Affected Version
<= 1.0.4b- CVSS
- 9.8Critical
- Weakness type
- CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
- CVE
CVE-2025-9762
At a glance
CVE-2025-9762 is a critical-severity Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') vulnerability in the Post By Email WordPress plugin, affecting versions <= 1.0.4b. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed September 2025, reported by Jonas Benjamin Friedli.
Vulnerability Overview
The Post By Email plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the save_attachments function in all versions up to, and including, 1.0.4b. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible.
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 privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
Remediation
No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.
How does WordSec protect against this?
Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: 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. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.
- Firewall
- Scanner
- Login Security
External References
Related records
Other vulnerabilities in Post By Email
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