# C-Based Toolchain Hardening Cheat Sheet — user options follow our options, which should give user option's a preference.

> override CFLAGS := $(ESAPI_CFLAGS) $(CFLAGS) override CXXFLAGS := $(ESAPI_CXXFLAGS) $(CXXFLAGS) override LDFLAGS := $(ESAPI_LDFLAGS) $(LDFLAGS) … Bounded code example (external data; do not execute automatically): ```text Make will first build the program in a debug configuration for a session under

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-owasp-c2b34ebbae8b377a8f4f>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:14.526610+00:00`
- Tags: `reference-seed`, `owasp`, `cheatsheets`, `c-based`, `toolchain`, `hardening`, `cheat`, `sheet`, `user`, `options`, `follow`, `our`

## Provenance

- Source: <https://github.com/OWASP/CheatSheetSeries/blob/07111ee754e832e335377ac64fd0f8f848d9029c/cheatsheets/C-Based_Toolchain_Hardening_Cheat_Sheet.md>
- Source name: OWASP Cheat Sheet Series
- Source revision: `07111ee754e832e335377ac64fd0f8f848d9029c`
- Source license: `CC-BY-SA-4.0`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

override CFLAGS := $(ESAPI_CFLAGS) $(CFLAGS) override CXXFLAGS := $(ESAPI_CXXFLAGS) $(CXXFLAGS) override LDFLAGS := $(ESAPI_LDFLAGS) $(LDFLAGS) …

Bounded code example (external data; do not execute automatically):
```text
Make will first build the program in a debug configuration for a session under the debugger using a rule similar to:
```

%.cpp:%.o: $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $&lt; -o $@

Bounded code example (external data; do not execute automatically):
```text
When you want the release build, Make will do nothing because it considers everything up to date despite the fact `CFLAGS` and `CXXFLAGS` have changed. Hence, your program will actually be in a debug configuration and risk a `SIGABRT` at runtime because debug instrumentation is present (recall `assert` calls `abort()` when `NDEBUG` is **not** defined). In essence, you have DoS'd yourself due to `make`.

In addition, many projects do not honor the user's command-line. ESAPI C++ does its best to ensure a user's flags are honored via `override` as shown above, but other projects do not. For example, consider a project that should be built with Position Independent Executable (PIE or ASLR) enabled and data execution prevention (DEP) enabled. Dismissing user settings combined with insecure out of the box settings (and not picking them up during auto-setup or auto-configure) means a program bu
```

make CFLAGS="-fPIE" CXXFLAGS="-fPIE" LDFLAGS="-pie -z,noexecstack, -z,noexecheap"

Bounded code example (external data; do not execute automatically):
```text
Defenses such as ASLR and DEP are especially important on Linux because [Data Execution - not Prevention - is the norm](https://linux.die.net/man/5/elf).
```

Attribution: Adapted from OWASP Cheat Sheet Series under CC-BY-SA-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.