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NotSanguine writes:

Dan Goodin over at Ars Technica is reporting about an OpenWRT vulnerability in its package manager, opkg.

From the article:

For almost three years, OpenWRT—the open source operating system that powers home routers and other types of embedded systems—has been vulnerable to remote code-execution attacks because updates were delivered over an unencrypted channel and digital signature verifications are easy to bypass, a researcher said.

[...] Security researcher Guido Vranken, however, recently found that updates and installation files were delivered over unencrypted HTTPs[sic] connections, which are open to attacks that allow adversaries to completely replace legitimate updates with malicious ones. The researcher also found that it was trivial for attackers with moderate experience to bypass digital-signature checks that verify a downloaded update as the legitimate one offered by OpenWTR maintainers. The combination of those two lapses makes it possible to send a malicious update that vulnerable devices will automatically install.

[...] These code-execution exploits are limited in their scope because adversaries must either be in a position to conduct a man-in-the-middle attack or tamper with the DNS server that a device uses to find the update on the Internet.

[...] Exploiting these weaknesses, Vranken was able to create a server that impersonated downloads.openwrt.org and served a malicious update. As long as the malicious file is the same size at the legitimate file, it will be executed by a vulnerable device.

Vranken backs up his claims in a blog post where he provides a proof-of-concept exploit against OpenWRT devices.

The checksum bypass vulnerability in OpenWRT's opkg has been assigned CVE-2020-7982.

Affected versions:
18.06.0-18.06.6
19.07.0
LEDE 17.01.0-17.01.7.

Original blog post with discussion and exploit code
OpenWRT Advisory for this vulnerability

OpenWRT is a Linux distro focused on embedded devices, supports a a variety of SoCs, and is widely used on home routers.

Original Submission