CVE-2017-8295

Wordpress Core < 5.5 - Unauthorized Password Reset via Interception

2017-05-03 00:00
Dawid Golunski

Strategic Overview

Status
Patched in 5.5
Affected Core
WordPress 5.5
Affected Version
< 5.5
CVSS
5.9Medium
Weakness type
CWE-640 · Weak Password Recovery Mechanism for Forgotten Password
CVE
CVE-2017-8295
View all WordPress 5.5 vulnerabilities

At a glance

CVE-2017-8295 is a medium-severity Weak Password Recovery Mechanism for Forgotten Password vulnerability in the WordPress 5.5 WordPress release line, affecting < 5.5. It carries a CVSS score of 5.9 (reachable over the network; high integrity impact). Exploitation requires no authentication. The issue is fixed in version 5.5; sites on affected versions should update now. Disclosed May 2017, reported by Dawid Golunski.

Vulnerability Overview

WordPress up to version 5.5 relies on the Host HTTP header for a password-reset e-mail message, which makes it easier for remote attackers to reset arbitrary passwords by making a crafted wp-login.php?action=lostpassword request and then arranging for this message to bounce or be resent, leading to transmission of the reset key to a mailbox on an attacker-controlled SMTP server. This is related to problematic use of the SERVER_NAME variable in wp-includes/pluggable.php in conjunction with the PHP mail function. Exploitation is not achievable in all cases because it requires at least one of the following: (1) the attacker can prevent the victim from receiving any e-mail messages for an extended period of time (such as 5 days), (2) the victim's e-mail system sends an autoresponse containing the original message, or (3) the victim manually composes a reply containing the original message.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on integrity.

CWE-640: Weak Password Recovery Mechanism for Forgotten Password

Reaching this weakness in WordPress 5.5 < 5.5 takes a caller who can reach the endpoint. A weak password recovery mechanism means the path that lets someone back into an account without their password is easier to complete than the password itself.

An attacker takes over an account through the recovery flow without ever seeing the password, and on an administrator account that is full control of the site. For WordPress 5.5 the fix is 5.5: builds < 5.5 are affected, anything from 5.5 onward is not.

Remediation

Update to version 5.5, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: updating to 5.5 is the step that ends it.

  • Login Security
  • Alerts

External References

Related records

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