Application security, DevOps

Cracked Concatenation, Injection Against DNS, Allstar GitHub, & DEF CON Highlights – ASW #162

This week in the AppSec News: Bug bounty report that cleverly manipulates a hash for profit, Allstar GitHub app to enforce security policies, choosing a programming language, what an app should log, adding security to DevOps, & manipulating natural-language models!

Full episode and show notes


  • In an overabundance of caution, we have decided to flip this year’s SW Unlocked to a virtual format. The safety of our listeners and hosts is our number one priority. We will miss seeing you all in person, but we hope you can still join us at Security Weekly Unlocked Virtual! The event will now take place on Thursday, Dec 16 from 9am-6pm ET. You can still register for free at

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Mike Shema
Mike Shema
Security Partner at Square
  1. 1. Steam security: Valve promptly resolves ‘unlimited funds’ gaming wallet cheat - This is a really cool and simple vuln -- a researcher noticed how Steam was concatenating name/value pairs when creating input to a hash function. The intent was to track the integrity of a request during a checkout flow. However, they made a subtle mistake in not placing delimiters among the concatenation, thus leaving an attacker able to influence the final string in a way that would allow them to make arbitrary transaction amounts. In other words, the semantic distinction got lost between what should have been a field like "amount" with a value like "2000" and "amount2" with a value like "000", which then enabled the attacker to sneak in an arbitrary amount value of their own. The take-away: The nature and cryptographic strength of a hash function doesn't matter if the assumptions in the data to be hashed are broken; include delimiters when hashing concatenated fields that may have user-influenced values. Be sure to check out the bug bounty report
  2. 2. Injection Attacks Reloaded: Tunnelling Malicious Payloads over DNS - This is a fun read even if you aren't familiar with the details of DNS. It hits two particularly favorite topics: Protocols and parsing. The researchers took some very simple payloads, like a NULL byte and escaped characters with a backslash, and found mismatches in how various libraries handled these within DNS packets. What's fun (from a security testing perspective) is that the researchers found new life in these very, very basic and very, very old payloads. It's a good lesson in parsing and handling data, with an extra challenge of keeping track of the semantic context of data separate from what syntax characters might show up in surprising places. That kind of issue is one reason we still struggle with XSS to this day. Check out the research paper at
  3. 3. Introducing the Allstar GitHub App - The Open Source Security Foundation continues to push on ways to mature the secure SDLC. In this case, they're looking at "continuous automated enforcement" of policies within a GitHub repo. The current list of policy and enforcement may be small, but the key is in have clear policies with actionable recommendations. And bonus points for automating the process so DevOps teams can focus on building software while their bots monitor for security issues.
  4. 4. Programming Languages: Choose Wisely? - Here's an article that gives us a chance to revisit programming languages and whether or in what ways security should influence what a team chooses. While there can be some technical reasons to build a case for or against a language, it's more likely that your processes and tooling -- combined with secure design -- will contribute to the security of an app more than the language will.
  5. 5. 5 best practices for designing application logs - "Have logs" shouldn't be the only recommendation a security team delivers to DevOps. It's important to understand the context of when logs will be used and what's helpful for them to contain. It's also important to be aware of the dangers of logging too much -- especially data like personal information or security tokens. Check out the related DEF CON talk at
  6. 6. DevSecOps: Merging Security and Software Engineering - Here's another talk that came out of this summer's slew of security conferences. The takeaway isn't so much about getting to a specific definition of DevOps or DevSecOps, but what it takes to bring security into a regular practice of software development. It includes some helpful examples of what worked and what didn't work when trying to engage DevOps teams. Check out the DEF CON video at
  7. 7. Cornell University researchers discover ‘code-poisoning’ attack - ML is the magic word that gets bandied about as a solution in all sorts of problem domains, including security. Regardless of whether it's fancy if-then statements or fancy math, the systems are complex and their normal operation can be difficult to understand. This research highlights once again how adversaries can ML models and take advantage of behavior in surprising ways. One way to generalize this idea beyond just ML is that, when threat modeling, make sure you have team that can be both creative about ways a system might be abused and enough domain knowledge to be able to evaluate risks that might be practical, hard, or hypothetical.
  8. 8. Researchers find vulnerabilities in Wodify gym management web application used with CrossFit - Some simple vulns that raise less simple questions. The vendor took quite a long time to respond to and resolve the bug, which sadly isn't uncommon for situations like this. That's usually a reflection of an org's appsec maturity or when bugs are complex and nuanced. Of course, there's nothing to nuanced about a classic XSS via img onerror. Another question is what design discussion or constraint led to an endpoint returning a user's hashed password as an intentional choice. Check out the original disclosure at
John Kinsella
John Kinsella
Co-founder & CTO at Cysense
  1. 1. AMD Secure Encrypted Virtualization undone by electrical attack - We've seen voltage "glitching" on smaller microcontrollers, but now researchers are seeing value in the method with modern "full" CPUs.
  2. 2. New RISCV design for quantum resistant security - One of the nice things about the RISCV architecture is the open source design which allows researchers to more easily create projects like this, to make it harder for quantum computers to break cryptography
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