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The 2019 Huawei cyber security evaluation report
The UK’s Huawei cyber security evaluation centre oversight board has released it’s 2019 annual report.
The header and footer of every page contains the text “SECRET”“OFFICIAL”, which I assume is its UK government security classification. It lends an air of mystique to what is otherwise a meandering management report.
Needless to say, the report contains the usually puffery, e.g., “HCSEC continues to have world-class security researchers…”. World class at what? I hear they have some really good mathematicians, but have serious problems attracting good software engineers (such people can be paid a lot more, and get to do more interesting work, in industry; the industry demand for mathematicians, outside of finance, is weak).
The most interesting sentence appears on page 11: “The general requirement is that all staff must have Developed Vetting (DV) security clearance, …”. Developed Vetting, is the most detailed and comprehensive form of security clearance in UK government (to quote Wikipedia).
Why do the centre’s staff have to have this level of security clearance?
The Huawei source code is not that secret (it can probably be found online, lurking in the dark corners of various security bulletin boards).
Is the real purpose of this cyber security evaluation centre, to find vulnerabilities in the source code of Huawei products, that GCHQ can then use to spy on people?
Or perhaps, this centre is used for training purposes, with staff moving on to work within GCHQ, after they have learned their trade on Huawei products?
The high level of security clearance applied to the centre’s work is the perfect smoke-screen.
The report claims to have found “Several hundred vulnerabilities and issues…”; a meaningless statement, e.g., this could mean one minor vulnerability and several hundred spelling mistakes. There is no comparison of the number of vulnerabilities found per effort invested, no comparison with previous years, no classification of the seriousness of the problems found, no mention of Huawei’s response (i.e., did Huawei agree that there was a problem).
How many vulnerabilities did the centre find that were reported by other people, e.g., the National Vulnerability Database? This information would give some indication of how good a job the centre was doing. Did this evaluation centre find the Huawei vulnerability recently disclosed by Microsoft? If not, why not? And if they did, why isn’t it in the 2019 report?
What about comparing the number of vulnerabilities found in Huawei products against the number found in vendors from the US, e.g., CISCO? Obviously back-doors placed in US products, at the behest of the NSA, need not be counted.
There is some technical material, starting on page 15. The configuration and component lifecycle management issues raised, sound like good points, from a cyber security perspective. From a commercial perspective, Huawei want to quickly respond to customer demand and a dynamic market; corners are likely to be cut off good practices every now and again. I don’t understand why the use of an unnamed real-time operating system was flagged: did some techie gripe slip through management review? What is a C preprocessor macro definition doing on page 29? This smacks of an attempt to gain some hacker street-cred.
Reading between the lines, I get the feeling that Huawei has been ignoring the centre’s recommendations for changes to their software development practices. If I were on the receiving end, I would probably ignore them too. People employed to do security evaluation are hired for their ability to find problems, not for their ability to make things that work; also, I imagine many are recent graduates, with little or no practical experience, who are just repeating what they remember from their course work.
Huawei should leverage its funding of a GCHQ spy training centre, to get some positive publicity from the UK government. Huawei wants people to feel confident that they are not being spied on, when they use Huawei products. If the government refuses to play ball, Huawei should shift its funding to a non-government, open evaluation center. Employees would not need any security clearance and would be free to give their opinions about the presence of vulnerabilities and ‘spying code’ in the source code of Huawei products.
Program analysis via information leakage
The use of software in high value transactions has created an interesting new field of software research that investigates the leakage of information from programs. The kind of information leaked, so-called sideband information, can take various forms, including:
- The amount of time taken to perform some operation. Many developers instinctively do their best to ensure that code does not take any longer to execute than it has to. In the case of one commonly used authentication system, the time taken to fail to authenticate an encryption key provided useful information on how close one trial encryption-key was compared to another (the closer the trial key to the actual key, the longer the authentication took to fail). The obvious implementation technique to foil this kind of attack is to add random delays into the authentication process.
It has even proved possible to perform timing attacks against a remote machine over the Internet to remote
- Use of some part of the value of secure information, by a system library function, to create the value passed back to the caller, e.g.,
if (secret_value & 0xf000) // Tell the caller that the top 'secret' four bits are set return 1; else return 0;
Researchers have been able to analyse the information flow of input values through some very large C programs.
- Analyse of network traffic routing information to work out who is talking to who. Various kinds of anonymizers have been created in attempt to make various forms of Internet traffic untraceable.
Any Internet program is accessible to information flow analysis. Using these techniques to analyse the search algorithm used by Google might be overly ambitious. A Google algorithm that might be within reach of is the one used by Adwords; the behavior of this algorithm is of interest to a growing number of people.
Information leakage techniques are becoming more widely known and developers working on programs containing a security component now need to consider how they can prevent information being leaked to attackers who sample program behavior looking for exploitable weaknesses.
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