CVE-2020-28339

Welcart e-Commerce <= 1.9.35 - PHP Object Injection

2020-11-05 00:00

Strategic Overview

Status: Patched in 1.9.36
Affected Plugin: Welcart e-Commerce
Affected Version: < 1.9.36
CVSS: 7.5High
Weakness type: CWE-502 · Deserialization of Untrusted Data
CVE: CVE-2020-28339

View all Welcart e-Commerce vulnerabilities

At a glance

CVE-2020-28339 is a high-severity Deserialization of Untrusted Data vulnerability in the Welcart e-Commerce WordPress plugin, affecting versions < 1.9.36. It carries a CVSS score of 7.5 (reachable over the network; high confidentiality, integrity, availability impact). The issue is fixed in version 1.9.36; sites on affected versions should update now. Disclosed November 2020, reported by Ram.

Vulnerability Overview

The usc-e-shop (aka Collne Welcart e-Commerce) plugin before 1.9.36 for WordPress allows Object Injection because of usces_unserialize. There is not a complete POP chain.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-502: Deserialization of Untrusted Data

Reaching this weakness in Welcart e-Commerce < 1.9.36 takes a caller who can reach the endpoint. Deserialization of untrusted data means the application reconstructs objects from input a caller controls, letting the attacker choose which classes get instantiated and what their properties hold.

A workable chain turns deserialization into file writes, deletions or code execution, depending on what the loaded classes do in their magic methods. For Welcart e-Commerce the fix is 1.9.36: builds < 1.9.36 are affected, anything from 1.9.36 onward is not.

Remediation

Update to version 1.9.36, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to Welcart e-Commerce: 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: Welcart e-Commerce 1.9.36 closes this, and updating the plugin is the step that ends it.

Firewall
Scanner
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2020-28339 https://www.wordfence.com/threat-intel/vulnerabilities/id/6c694bce-e389-492a-827d-ae5293730612 https://nvd.nist.gov/vuln/detail/CVE-2020-28339

Related records

Same weakness class

Other vulnerabilities in Welcart e-Commerce

CVSS Vector

7.5

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

Base

Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

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