Blog entry by Les Bell

Les Bell
by Les Bell - Tuesday, February 13, 2024, 11:12 AM
Anyone in the world

One of my personal security mantras is: The enemy of security is complexity. A fascinating post in IEEE Spectrum makes the same point, specifically about contemporary approaches to software development.


In "Why Bloat Is Still Software's Biggest Vulnerability", Bert Hubert calls out software architects and developers generally over the dire state of software security, pointing to the last year's highly-publicized exploitations of Ivanti, MOVEit, Outlook, Confluence, Barracuda Email Security Gateway and the Citrix NetScaler products - to name just a few.

The current software market actually penalizes developers who take the time to deal with security properly. The market continuously demands new software, with more and more sophisticated features (if your product doesn't incorporate AI in some form, you're dead in the water). At the same time, customers prize convenience, and there's a huge advantage to the first movers in the market - hence a focus on shipping a minimum viable product before the seed capital runs out. Security? Well, we can figure that out later.

A particular problem is the increasing reliance on third-party - usually open-source - libraries sourced from repositories which may themselves have vulnerabilities. Hubert points to one, relatively simple, photo-sharing application which has 1,600 dependencies on external libraries (!). This provides an attacker with an enormous attack surface which is largely beyond the control of both the central application developer and the user.

External libraries are well-nigh essential when a product has to provide a wide range of functionality. As Hubert explains, the Barracuda Email Security Gateway vulnerability lay in the way a third-party Perl module would unpack Excel spreadsheets to scan them for malware - allowing arbitrary code execution as it did so. But if you're a security pro working on a mail gateway product, do you want to invest the time and effort required to write your own code to securely parse a spreadsheet file? I thought not.

To Hubert's credit, he puts his money where his mouth is by developing a lean image-sharing program that consists of just 1,600 lines of source code plus five important dependencies.

Is there an answer to the increasing complexity of software, along with the exponentially-growing attack surface it presents? It would be a brave man that pushes back against the demand for do-everything functionality, especially in a security product. But I can't help wondering how many times the Barracuda product actually saved a completely naive user from opening a spreadsheet and allowing it run a malware macro, versus how many organizations' networks were exploited via the vulnerability in the email gateway.

The US Cybersecurity & Infrastructure Security Agency has partnered with the Open Source Security Foundation (OpenSSF) Securing Software Repositories Working Group to publish the Principles for Package Repository Security framework. This defines four levels of security maturity for package repositories to be measured in areas sich as authentication, authorization, CLI tooling and general capabilities. This at least allows the establishment of a roadmap to secure that end of the software supply chain.

In the meantime, I know I'll be pursuing a lean approach wherever possible.

Cable, Jack and Zach Steindler, Principles for Package Repository Security, Open Source Security Foundation, February 2024. Available online at https://repos.openssf.org/principles-for-package-repository-security.

Hubert, Bert,  Why Bloat Is Still Software’s Biggest Vulnerability: A 2024 plea for lean software, IEEE Spectrum, 8 February 2024. Available online at https://spectrum.ieee.org/lean-software-development.


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