PT-2018-34: XXE Injection in S3 Browser

(PT-2018-34) Positive Technologies Security Advisory
XXE Injection in S3 Browser

Vulnerable software

S3 Browser
Version: 7.x and earlier

Link:
https://s3browser.com/

Severity level

Severity level: Medium
Impact: Partial user-file reading, obtaining user NTLMv2 hash
Access Vector: Remote

CVSS v3:
Base Score: 6.9
Vector: (AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:N)

CVE: CVE-2018-20298

Vulnerability description

The specialists of the Positive Research center have detected an XXE Injection vulnerability in S3 Browser.

A vulnerability in the HTTP-based S3 protocol, due to server responses transmitted in XML format, allows remote attackers to read user files and obtain NTLMv2 hash values by tricking a user into connecting to a malicious server.

How to fix

Update your software up to the latest version

Advisory status

09.10.2018 - Vendor gets vulnerability details
18.12.2018 - Vendor releases fixed version and details
18.12.2018 - Public disclosure

Credits

The vulnerability was detected by Igor Kanygin, Positive Research Center (Positive Technologies Company)

References

http://en.securitylab.ru/lab/PT-2018-34

Reports on the vulnerabilities previously discovered by Positive Research:

https://www.ptsecurity.com/
https://en.securitylab.ru/lab/

About Positive Technologies

Positive Technologies is a leading digital security firm with over 15 years of experience in 360 protection of critical IT systems against the most advanced cyberthreats. State-of-the-art solutions are developed at the company's research centerone of the largest in Europe. Positive Technologies experts have helped to identify and fix over 250 zero-day vulnerabilities in products from Cisco, Google, Honeywell, Huawei, Microsoft, Oracle, SAP, Schneider Electric, Siemens, and others, earning a reputation for world-class expertise in protection of devices and infrastructures at all scales from ATMs to nuclear power stations. Findings by Positive Technologies researchers are used for updating the MaxPatrol knowledge base and for development of security solutions including PT Application Firewall, PT Application Inspector, MaxPatrol. These products allow securing web applications, evaluating network protection, blocking attacks in real time, ensuring compliance with industry and national standards, and training security specialists. Positive Technologies is the organizer of the annual Positive Hack Days international forum and security competition.