CVE-2016-4029

WordPress Core < 4.5 - Server-Side Request Forgery

2016-09-29 00:00

Strategic Overview

Status: Patched in 4.5
Affected Core: WordPress 4.5
Affected Version: < 4.5
CVSS: 5.0Medium
Weakness type: CWE-918 · Server-Side Request Forgery (SSRF)
CVE: CVE-2016-4029

At a glance

CVE-2016-4029 is a medium-severity Server-Side Request Forgery (SSRF) vulnerability in the WordPress 4.5 WordPress release line, affecting < 4.5. It carries a CVSS score of 5.0 (reachable over the network; low attack complexity). The issue is fixed in version 4.5; sites on affected versions should update now. Disclosed September 2016.

Vulnerability Overview

WordPress before 4.5 does not consider octal and hexadecimal IP address formats when determining an intranet address, which allows remote attackers to bypass an intended SSRF protection mechanism via a crafted address.

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.

CWE-918: Server-Side Request Forgery (SSRF)

Reaching this weakness in WordPress 4.5 < 4.5 takes a caller who can reach the endpoint. Server-side request forgery means the application fetches a URL supplied by the caller, turning the server into a proxy for requests the attacker could not make directly.

The request originates from inside the hosting network, which is how these flaws reach cloud metadata endpoints, internal admin panels and services that trust local traffic. For WordPress 4.5 the fix is 4.5: builds < 4.5 are affected, anything from 4.5 onward is not.

Remediation

Update to version 4.5, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to WordPress 4.5: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: updating to 4.5 is the step that ends it.

Firewall
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2016-4029 https://www.wordfence.com/threat-intel/vulnerabilities/id/ea26eb81-e6d1-4c6d-95f4-fd1b2d919632 https://nvd.nist.gov/vuln/detail/CVE-2016-4029

Related records

Same weakness class

Other vulnerabilities in WordPress 4.5

CVSS Vector

5.0

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeChanged
ConfidentialityLow
IntegrityNone
AvailabilityNone

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