Security watchers have reacted positively to recently announced improvements to Microsoft's Edge browser, which had earned an unenviable reputation for easy pwnage.

Redmond is reducing its exposure to malicious exploits by improving Edge's sandboxing technology. Further features have been added to existing technologies like ACG (Arbitrary Code Guard) and CIG (Code Integrity Guard) to prevent remote code execution.

ACG1 and CIG2 are designed to make it harder for hackers to load malicious code into memory. Edge omits support for the ActiveX or Browser Helper Objects technologies of Internet Explorer so it is able to run entirely inside app container sandboxes at all times. The improved defences are designed to better guard against so-called drive-by download attacks.

The security revamp focuses on reducing the attack surface of the software. To this end, Microsoft's app containers have been redesigned to reduce the amount of code in the sandbox. Developers have also incorporated less privileged and custom-crafted app containers in order to make life harder for potential hackers.

"We will continue to invest in both RCE and sandbox mitigations for Microsoft Edge," said senior program manager Crispin Cowan. "These exploit mitigations combined with the strengthened sandboxing should make Microsoft Edge significantly more work for attackers to exploit, and thus discourage attackers from trying in the first place."

Microsoft Edge app container model [Source: Microsoft]

The changes are welcome not least because Microsoft Edge was the most-hacked browser at the recent Pwn2Own event. The weak security issues extend into the real world beyond the high-profile hacker event. For example, Google Project Zero has uncovered a number of security flaws with previous iterations of the browser, most recently an unpatched Microsoft Edge and IE vulnerability (CVE-2017-0037) last month.

Despite its previously lacklustre reputation, experts are by no means down on Microsoft's browser technology. Several are positive about Microsoft's security roadmap.

Marco Cova, senior security researcher at malware detection firm Lastline, commented: "Microsoft is definitely on the right track here. Reducing the privileged operations available to untrusted code and containing it in sandboxes so that exploits are harder to pull off successfully are the two best ways we know to build secure systems.

"It sounds like a great engineering feat on their part. Of course, the devil is in the details of how they actually implemented these mechanisms, and I'm sure quite a few people will be testing them extensively in the near future."

Security consultant Kevin Beaumont‏ is also upbeat about Edge. "Microsoft Edge is actually a great browser for corp use and some of the upcoming security features are killer," he said in a Twitter update.

Microsoft Edge features in the Creators Update of Windows 10, a broader operating system update covered in more depth here. ®

1ACG is meant to ensure code cannot be dynamically generated or modified

2CIG is designed so that only properly signed images can load