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

Flaws Reported in Bank of America System

Sestus, rival to vendor of Bank of America's SiteKey authentication system, reports vulnerabilities in the Sitekey technology

The authentication technology used by Sitekey, Bank of America's online customer service system, is flawed and could make the bank vulnerable to denial-of-service attacks, a vendor said yesterday in a report that was disputed by both the bank and its primary contractor.

The two-factor authentication system offered by Bank of America, which allows a user to select a separate image file to help verify his/her identity, was developed by Passmark, an authentication tool vendor now owned by RSA Security.

But in a bit of vendor gamesmanship, the vulnerability report was issued by Sestus, a Passmark rival that also makes multi-factor authentication technology. Sestus, maker of PhishCops, has been critical of the Passmark technology in the past, publishing other documents that put Sitekey in a negative light.

In this case, however, Sestus reported the discovery of a "previously unreported vulnerability" in the Bank of America system that would enable an attacker to exploit the bank's lockout process to launch a denial-of-service attack on Sitekey, effectively preventing customers from accessing their accounts online.

"It appears that this lockout process can be exploited by malicious hackers to remotely lock out customers from their accounts en masse, or used by fraudsters in a hybrid lockout/phishing attack to access the actual account," the report said. The researchers did not publish a proof of concept with the vulnerability report.

In a series of three different scenarios, Sestus described how an attacker might use scripts and commonly-used login words to guess Bank of America customer login information, then type invalid information when the system requests the second authentication factor. Such an exploit would effectively lock users out of their accounts and tie up Bank of America systems, the vendor said. Attackers might also create a look-alike "error" page to phish personal information away from frustrated users, according to the report.

The vulnerability is not unique to Sitekey, but it could be exploited in any system that requests personal information before verifying the authenticity of the Web page, Sestus observed.

According to a Bank of America spokeswoman, the vulnerability doesn't threaten the safety of users' data. "It's not an issue that poses a risk to customers' information," she says. However, the vulnerability could lock out users if a hacker launched a denial-of-service attack, she says, and "anything that would be an inconvenience to our customers would be a concern for us."

Louie Gasparini, CTO of the RSA unit that now owns the Passmark technology, put a finer point on his response. "There's no vulnerability here that hasn't been in online banking systems for the past 10 years," he says. "This is the way the [banking authentication] system has always worked, and it's not unique to Sitekey or Passmark."

— Tim Wilson, Site Editor, Dark Reading

  • RSA Security Inc. (Nasdaq: EMC)
  • Sestus Data Corp.

    Tim Wilson is Editor in Chief and co-founder of Dark Reading.com, UBM Tech's online community for information security professionals. He is responsible for managing the site, assigning and editing content, and writing breaking news stories. Wilson has been recognized as one ... View Full Bio

    Comment  | 
    Print  | 
    More Insights
  • Comments
    Newest First  |  Oldest First  |  Threaded View
    COVID-19: Latest Security News & Commentary
    Dark Reading Staff 9/25/2020
    Hacking Yourself: Marie Moe and Pacemaker Security
    Gary McGraw Ph.D., Co-founder Berryville Institute of Machine Learning,  9/21/2020
    Startup Aims to Map and Track All the IT and Security Things
    Kelly Jackson Higgins, Executive Editor at Dark Reading,  9/22/2020
    Register for Dark Reading Newsletters
    White Papers
    Current Issue
    Special Report: Computing's New Normal
    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
    How IT Security Organizations are Attacking the Cybersecurity Problem
    How IT Security Organizations are Attacking the Cybersecurity Problem
    The COVID-19 pandemic turned the world -- and enterprise computing -- on end. Here's a look at how cybersecurity teams are retrenching their defense strategies, rebuilding their teams, and selecting new technologies to stop the oncoming rise of online attacks.
    Twitter Feed
    Dark Reading - Bug Report
    Bug Report
    Enterprise Vulnerabilities
    From DHS/US-CERT's National Vulnerability Database
    PUBLISHED: 2020-09-25
    In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, when determining the common dimension size of two tensors, TFLite uses a `DCHECK` which is no-op outside of debug compilation modes. Since the function always returns the dimension of the first tensor, malicious attackers can ...
    PUBLISHED: 2020-09-25
    In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, a crafted TFLite model can force a node to have as input a tensor backed by a `nullptr` buffer. This can be achieved by changing a buffer index in the flatbuffer serialization to convert a read-only tensor to a read-write one....
    PUBLISHED: 2020-09-25
    In tensorflow-lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, if a TFLite saved model uses the same tensor as both input and output of an operator, then, depending on the operator, we can observe a segmentation fault or just memory corruption. We have patched the issue in d58c96946b and ...
    PUBLISHED: 2020-09-25
    In TensorFlow Lite before versions 1.15.4, 2.0.3, 2.1.2, 2.2.1 and 2.3.1, saved models in the flatbuffer format use a double indexing scheme: a model has a set of subgraphs, each subgraph has a set of operators and each operator has a set of input/output tensors. The flatbuffer format uses indices f...
    PUBLISHED: 2020-09-25
    In TensorFlow Lite before versions 2.2.1 and 2.3.1, models using segment sum can trigger writes outside of bounds of heap allocated buffers by inserting negative elements in the segment ids tensor. Users having access to `segment_ids_data` can alter `output_index` and then write to outside of `outpu...