6550e65756
Improvement identified in #2790. Add a prefix to the diff-id when it is used multiple times in different "how to fix it in XYZ" sections to avoid ambiguity and pedantically follow the spec: > A single and unique diff-id should be used only once for each type of code example as shown in the description of a rule. Obvious typos around `diff-type` were fixed.
62 lines
1.8 KiB
Plaintext
62 lines
1.8 KiB
Plaintext
== How to fix it in Symfony
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=== Code examples
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include::../../common/fix/code-rationale.adoc[]
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==== Noncompliant code example
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[source,php,diff-id=11,diff-type=noncompliant]
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----
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public function unsafe(Request $request): JsonResponse
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{
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$process = Process::fromShellCommandline($request->query->get("cmd")); // Noncompliant
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$process->run();
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$code = $process->wait();
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return $this->json($code == 0);
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}
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----
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==== Compliant solution
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[source,php,diff-id=11,diff-type=compliant]
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----
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public function safe(Request $request): JsonResponse
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{
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$allowedCommands = [["/bin/ping","-c","1","--"],["/usr/bin/host","--"]];
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$cmd = $allowedCommands[$request->query->get("cmdId")];
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$cmd[] = $request->query->get("host");
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$process = new Process($cmd);
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$process->run();
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$code = $process->wait();
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return $this->json($code == 0);
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}
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----
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=== How does this work?
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include::../../common/fix/introduction.adoc[]
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include::../../common/fix/pre-approved-list.adoc[]
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In the example compliant code, a static list of allowed commands is used.
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Users are only allowed to provide a command index that will be used to access
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this list. The command resulting from the list access can be considered
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trusted.
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:sanitizationLib: Symfony\Component\Process\Process
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include::../../common/fix/sanitize-meta-characters.adoc[]
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In the example compliant code, the `Process` constructor is used in place of
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the less safe `fromShellCommandline` function. It accepts a list of command
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arguments that will be properly escaped and concatenated to form the command
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line to execute.
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include::../../common/fix/shell_integration.adoc[]
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In the example compliant code, using the `Process` constructor is preferred
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over the less safe `fromShellCommandline` `Process` factory. This way of
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creating `Process` instances disables shell integration by default.
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