CVE-2021-24312

WP Super Cache <= 1.7.2 - Authenticated Remote Code Execution

2021-05-14 00:00
NGA

Strategic Overview

Status
Patched in 1.7.3
Affected Plugin
WP Super Cache
Affected Version
< 1.7.3
CVSS
7.2High
Weakness type
CWE-94 · Improper Control of Generation of Code ('Code Injection')
CVE
CVE-2021-24312
View all WP Super Cache vulnerabilities

At a glance

CVE-2021-24312 is a high-severity Improper Control of Generation of Code ('Code Injection') vulnerability in the WP Super Cache WordPress plugin, affecting versions < 1.7.3. 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 1.7.3; sites on affected versions should update now. Disclosed May 2021, reported by NGA.

Vulnerability Overview

The parameters $cache_path, $wp_cache_debug_ip, $wp_super_cache_front_page_text, $cache_scheduled_time, $cached_direct_pages used in the settings of WP Super Cache WordPress plugin before 1.7.3 result in RCE because they allow input of '$' and '\n'. This is due to an incomplete fix of CVE-2021-24209.

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-94: Improper Control of Generation of Code ('Code Injection')

WP Super Cache < 1.7.3 carries this weakness at and, and reaching it takes any authenticated account. Code injection means input from a request reaches a language construct that evaluates code, so the attacker's text is executed rather than treated as data.

The injected code runs with the web server's privileges, giving the attacker the same access to the database and filesystem as WordPress itself. For WP Super Cache the fix is 1.7.3: builds < 1.7.3 are affected, anything from 1.7.3 onward is not.

Remediation

Update to version 1.7.3, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to WP Super Cache: 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: WP Super Cache 1.7.3 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24312https://www.wordfence.com/threat-intel/vulnerabilities/id/733ae8c8-fa52-418d-b42e-75516906fb66https://nvd.nist.gov/vuln/detail/CVE-2021-24312

Related records

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