Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Vulnerabilities / Threats

D-Link Router Vulnerable To Authentication Bypass

Multiple D-Link, Planex and Virgin Mobile routers have a firmware vulnerability that attackers could exploit to directly access and alter the devices.

Multiple D-Link routers are vulnerable to a simple exploit that would allow an attacker to gain direct access to the device without first having to authenticate.

That warning came in a Saturday post to embedded device hacking blog /dev/ttyS0 written by Craig Heffner, a vulnerability researcher with Tactical Network Solutions.

"On a whim I downloaded firmware v1.13 for the DIR-100 revA," Heffner said, referring to a widely used version of D-Link's router firmware. After using a firmware analysis tool known as Binwalk, "soon I had the firmware's Web server (/bin/webs) loaded into IDA," he added, referring to an interactive disassembler -- IDA -- which is used to reverse-engineer code.

Perusing the code, Heffner found a variable called "alpha_auth_check" -- the "alpha" apparently refers to D-Link spinoff Alpha Networks, while "auth" means "authentication" -- that returns a value of "1" if the user has been authenticated. After a bit of exploratory work, Heffner found that if he changed a browser's HTTP user-agent string to "xmlset_roodkcableoj28840ybtide" then "you can access the Web interface without any authentication and view/change the device settings."

[ Don't be a victim. See 15 Signs Pointing To A Data Breach. ]

Heffner doesn't appear to be the first person to have recovered this string from inside the D-Link firmware. "A quick Google for the 'xmlset_roodkcableoj28840ybtide' string turns up only a single Russian forum post from a few years ago, which notes that this is an 'interesting line' inside the /bin/webs binary," he said. "I'd have to agree."

A spokesman for D-Link didn't immediately respond to an emailed query about whether it had verified the vulnerability detailed by Heffner, and if so, how the company planned to notify and issue updates to consumers who own a vulnerable device.

Based on a search made with the embedded Web server search engine Shodan, the vulnerable firmware appears to be used by at least seven routers sold by D-Link (DIR-100, DI-524, DI-524UP, DI-604S, DI-604UP, DI-604+, TM-G5240) as well as two Planex routers (BRL-04UR, BRL-04CW), according to Heffner. "Several people have reported ... that some versions of the DIR-615 are also affected, including those distributed by Virgin Mobile," he said in a later update to his blog post. "I have not yet verified this, but it seems quite reasonable."

What's the count of the total number of networked D-Link devices that are affected by the vulnerability? That remains to be seen, although Robert David Graham, CEO of Errata Security, said Monday that he was "scanning the entire Internet for the D-Link 'xmlset_roodkcableoj28840ybtide' backdoor" using his Masscan tool, which can be used to scan the Internet for certain variables, which in this case would be fingerprints of the vulnerable firmware. Graham said he hoped to be able to report on the results of his scan by Monday afternoon.

What's the risk from an attacker gaining full access to a router? For starters, the attacker could eavesdrop on the network by loading the router with custom firmware designed to send a copy of all data flowing to or from the device to an attacker-controlled server. Likewise, the router could be configured to automatically launch distributed denial-of-service attacks against designated sites.

As Heffner's facility with reverse-engineering device firmware suggests, this isn't his first foray into hacking networking equipment. At this past summer's Black Hat conference in Las Vegas, for example, the researcher highlighted how consumer-grade as well as enterprise-class networked surveillance cameras from the likes of D-Link, Trendnet, Cisco, IQInvision, Alinking and 3SVision were vulnerable to zero-day flaws that would allow an attacker to freeze or modify their video streams. That research was the latest in a long line of vulnerability reports involving Internet protocol (IP) cameras.

 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
OtherJimDonahue
50%
50%
OtherJimDonahue,
User Rank: Apprentice
10/15/2013 | 8:22:01 PM
re: D-Link Router Vulnerable To Authentication Bypass
Well, guess what I'll be checking when I go home tonight! (No idea what my D-Link model number is.)
COVID-19: Latest Security News & Commentary
Dark Reading Staff 7/13/2020
Omdia Research Launches Page on Dark Reading
Tim Wilson, Editor in Chief, Dark Reading 7/9/2020
Russian Cyber Gang 'Cosmic Lynx' Focuses on Email Fraud
Kelly Sheridan, Staff Editor, Dark Reading,  7/7/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
Special Report: Computing's New Normal, a Dark Reading Perspective
This special report examines how IT security organizations have adapted to the "new normal" of computing and what the long-term effects will be. Read it and get a unique set of perspectives on issues ranging from new threats & vulnerabilities as a result of remote working to how enterprise security strategy will be affected long term.
Flash Poll
The Threat from the Internetand What Your Organization Can Do About It
The Threat from the Internetand What Your Organization Can Do About It
This report describes some of the latest attacks and threats emanating from the Internet, as well as advice and tips on how your organization can mitigate those threats before they affect your business. Download it today!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-14300
PUBLISHED: 2020-07-13
The docker packages version docker-1.13.1-108.git4ef4b30.el7 as released for Red Hat Enterprise Linux 7 Extras via RHBA-2020:0053 (https://access.redhat.com/errata/RHBA-2020:0053) included an incorrect version of runc that was missing multiple bug and security fixes. One of the fixes regressed in th...
CVE-2020-14298
PUBLISHED: 2020-07-13
The version of docker as released for Red Hat Enterprise Linux 7 Extras via RHBA-2020:0053 advisory included an incorrect version of runc missing the fix for CVE-2019-5736, which was previously fixed via RHSA-2019:0304. This issue could allow a malicious or compromised container to compromise the co...
CVE-2020-15050
PUBLISHED: 2020-07-13
An issue was discovered in the Video Extension in Suprema BioStar 2 before 2.8.2. Remote attackers can read arbitrary files from the server via Directory Traversal.
CVE-2020-10987
PUBLISHED: 2020-07-13
The goform/setUsbUnload endpoint of Tenda AC15 AC1900 version 15.03.05.19 allows remote attackers to execute arbitrary system commands via the deviceName POST parameter.
CVE-2020-10988
PUBLISHED: 2020-07-13
A hard-coded telnet credential in the tenda_login binary of Tenda AC15 AC1900 version 15.03.05.19 allows unauthenticated remote attackers to start a telnetd service on the device.