CVE-2022-1091

Safe SVG <= 1.9.9 - Content-Type Bypass

2022-03-25 00:00
David Hamann

Strategic Overview

Status
Patched in 1.9.10
Affected Plugin
Safe SVG
Affected Version
< 1.9.10
CVSS
7.7High
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2022-1091
View all Safe SVG vulnerabilities

At a glance

CVE-2022-1091 is a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Safe SVG WordPress plugin, affecting versions < 1.9.10. It carries a CVSS score of 7.7 (reachable over the network; low attack complexity; high integrity impact). The issue is fixed in version 1.9.10; sites on affected versions should update now. Disclosed March 2022, reported by David Hamann.

Vulnerability Overview

The sanitisation step of the Safe SVG WordPress plugin before 1.9.10 can be bypassed by spoofing the content-type in the POST request to upload a file. Exploiting this vulnerability, an attacker will be able to perform the kinds of attacks that this plugin should prevent (mainly XSS, but depending on further use of uploaded SVG files potentially other XML attacks).

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 integrity.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in Safe SVG < 1.9.10 takes a caller who can reach the endpoint. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Safe SVG the fix is 1.9.10: builds < 1.9.10 are affected, anything from 1.9.10 onward is not.

Remediation

Update to version 1.9.10, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Safe SVG: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Safe SVG 1.9.10 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Alerts

External References

Related records

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