Auth bypass in Western Digital My Cloud Dl2100
CVE-2018-17153
It was discovered that the Western Digital My Cloud device before 2.30.196 is affected by an authentication bypass vulnerability. An unauthenticated attacker can exploit this vulnerability to authenticate as an admin user without needing to provide a password, thereby gaining full control of the device. (Whenever an admin logs into My Cloud, a server-side session is created that is bound to the user's IP address. After the session is created, it is possible to call authenticated CGI modules by sending the cookie username=admin in the HTTP request. The invoked CGI will check if a valid session is present and bound to the user's IP address.) It was found that it is possible for an unauthenticated attacker to create a valid session without a login. The network_mgr.cgi CGI module contains a command called "cgi_get_ipv6" that starts an admin session -- tied to the IP address of the user making the request -- if the additional parameter "flag" with the value "1" is provided. Subsequent invocation of commands that would normally require admin privileges now succeed if an attacker sets the username=admin cookie.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.866 (99.7th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.866 · newest: 0.866 · change: 0.000
Affected products
- Western Digital My Cloud Dl2100
- Western Digital My Cloud Dl4100
- Western Digital My Cloud Dl4100 Firmware
- Western Digital My Cloud Ex2
- Western Digital My Cloud Ex2100
- Western Digital My Cloud Ex2100 Firmware
- Western Digital My Cloud Ex2 Firmware
- Western Digital My Cloud Ex2 Ultra
- Western Digital My Cloud Ex2 Ultra Firmware
- Western Digital My Cloud Ex4
Weakness classification (CWE)
Public proof-of-concept exploits
References
- www.securityfocus.com/bid/105359 (VDB Entry, Third Party Advisory, vdb-entry)
- securify.nl/nl/advisory/SFY20180102/authentication-bypass-vulnerability-in-west… (Exploit, Third Party Advisory)
- support.wdc.com/knowledgebase/answer.aspx (Third Party Advisory)
- packetstormsecurity.com/files/173802/Western-Digital-MyCloud-Unauthenticated-Co…
Frequently asked questions
- What is CVE-2018-17153?
- CVE-2018-17153 is a critical-severity vulnerability in Western Digital My Cloud Dl2100, classified under Improper Authentication. CVSS score: 9.8/10. Published 2018-09-18.
- How severe is CVE-2018-17153?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2018-17153 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.