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.

Infrastructure Security //

DNS

1/24/2019
09:35 AM
Larry Loeb
Larry Loeb
Larry Loeb
50%
50%

DNS Tampering Prompts Homeland Security Warning

Despite the partial federal government shutdown, DHS has managed to issue a warning to the public about possible tampering with DNS addresses that appear to have originated in Iran.

The US Department of Homeland Security's Cybersecurity and Infrastructure Security Agency (CISA) has issued an emergency directive that addresses ongoing incidents ascribed to global Domain Name System (DNS) infrastructure tampering.

Yes, in the middle of the self-inflicted shutdown the US government is freaking out.

The DNS hijacking effort has now been found to be affecting government domains. The summary page of the emergency directive uses links that refer to the hijackings -- attributed to Iran -- that have been previously reported by Talos and FireEye.

In a notice, CISA asserts that it is aware of multiple executive branch agency domains that were affected by the tampering campaign and has notified the agencies that maintain them. The agency describes the attack methodology it has encountered, which seems very similar to those which have been already described by the security companies.

The attacker begins by compromising user credentials -- or obtaining them through alternate means -- of an account that can make changes to DNS records.

The attacker alters DNS records, such as Address (A), Mail Exchanger (MX), or Name Server (NS) records, replacing the legitimate address of a service with an address that the attacker controls. It can then pass the traffic on to the legitimate address. This threat lasts beyond the period of traffic redirection.

With the change in DNS records, the attacker can obtain valid encryption certificates for an organization's domain names. This allows the redirected traffic to be decrypted, exposing any user-submitted data. Since the certificate is valid for the domain, end users receive no error warnings.

The directive specifies certain steps that it directs affected agencies to take within the next ten business days from January 22:

  • Audit DNS records associated with government domains to verify that they have not been tampered with and are directing traffic to the correct IP addresses.
  • Change the passwords for DNS admin accounts that modify DNS records.
  • Add multi-factor authentication (MFA) to all DNS admin accounts. It should be noted that the CISA has in the past advised against the use of SMS-based MFA.
  • Begin to monitor the Certificate Transparency (CT) logs for agency domains that will be provided by DHS within the next ten business days.

These steps have no termination date associated with them, although they could be terminated by another directive.

Affected agencies will need to submit a status report by Friday, January 2, and a completion report that all of the actions have been completed by February 5.

Related posts:

— Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other things, a consulting editor for BYTE magazine and senior editor for the launch of WebWeek.

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
Video
Cartoon
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
CVE-2020-15208
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 ...
CVE-2020-15209
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....
CVE-2020-15210
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 ...
CVE-2020-15211
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...
CVE-2020-15212
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...