Add PR_3_cpp detector files by branedev2 · Pull Request #11 · branedev2/pr_on_dl_old

branedev2 · 2025-07-15T13:29:21Z

No description provided.

amazon-q-developer · 2025-07-15T13:29:25Z

⏳ I'm reviewing this pull request for security vulnerabilities and code quality issues. I'll provide an update when I'm done

gemini-code-assist

Summary of Changes

Hello @branedev2, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request expands the existing C/C++ detector suite by adding new example files that demonstrate both secure (compliant) and insecure (non-compliant) coding practices for various security rules. These additions serve to provide clear, actionable illustrations for developers and security analysts to understand and mitigate common vulnerabilities in C/C++ applications.

Highlights

New C/C++ Detector Examples: This PR introduces a comprehensive set of compliant and non-compliant code examples for 13 distinct C/C++ security rules. These examples cover common vulnerabilities such as clear-text protocols, divide-by-zero, improper input validation, insecure temporary files, and incorrect pointer scaling, among others. Each example is designed to illustrate the specific security rule and its corresponding defect status.

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amazon-q-developer · 2025-07-15T13:30:37Z

+    free(var);
+
+    // Noncompliant: Using memory after it has been freed.
+    strcpy(buf, (char*)var);


Caution
Description: Accessing already freed memory can lead to critical issues like data corruption or unintended code execution, depending on how and when the memory is reused. This scenario resembles repurposing memory intended for release, resulting in unpredictable behavior and security vulnerabilities. To prevent such issues, practice careful memory management, ensuring proper allocation and deallocation procedures are followed, and avoid accessing memory after it has been freed. Learn more - https://owasp.org/www-community/vulnerabilities/Using_freed_memory

Severity: Critical

The fix removes the strcpy operation that was using freed memory and sets the pointer to NULL after freeing to prevent accidental use of the freed memory.

Suggested change

strcpy(buf, (char*)var);

int compliant() {

NAME *var;

char buf[10];

var = (NAME *)malloc(sizeof(struct name));

if (var == NULL) {

printf("Memory allocation failed

");

return 1;

}

// Remove the strcpy operation that uses freed memory

free(var);

var = NULL; // Set the pointer to NULL after freeing

return 0;

}

amazon-q-developer · 2025-07-15T13:30:37Z

+void noncompliant() {
+
+    // Noncompliant: setgid() is called after setuid(), which may fail to drop privileges properly.
+    setuid(getuid());


Caution
Description: Improper ordering of set(e)gid() and set(e)uid() calls can lead to security vulnerabilities. A compromised process might be able to regain elevated group privileges if set(e)gid() is called after set(e)uid(). A similar case is when privileges are temporarily dropped with seteuid() and then setuid() or seteuid() are called from while under unprivileged user. Learn more : https://cwe.mitre.org/data/definitions/696.html

Severity: Critical

The fix involves reordering the privilege-dropping calls by placing setgid() before setuid(). This ensures that group privileges are dropped before user privileges, preventing potential security vulnerabilities.

Suggested change

setuid(getuid());

void noncompliant() {

// Call setgid() before setuid() to properly drop privileges

setgid(getgid());

setuid(getuid());

}

amazon-q-developer · 2025-07-15T13:30:38Z

+
+typedef int CURLoption;
+
+CURL* curl_easy_init()


Caution
Description: Function curl_easy_init() returns an uninitialized pointer, which can lead to undefined behavior. Initialize the 'curl' pointer before returning it or return NULL if initialization fails.

Severity: Critical

The fix addresses the issue of returning an uninitialized pointer in the curl_easy_init() function. The 'curl' pointer is now initialized to NULL before being returned. A TODO comment is added to remind the developer to implement proper initialization of the curl handle. This change prevents undefined behavior that could occur when using an uninitialized pointer, but a complete fix would require actual initialization of the curl handle.

Suggested change

CURL* curl_easy_init()

CURL* curl_easy_init()

{

CURL *curl = NULL;

// TODO: Implement proper initialization of curl

return curl;

}

amazon-q-developer · 2025-07-15T13:30:40Z

+
+    // Noncompliant: Use of the `chroot` function, which may lead to security vulnerabilities.
+    const char* root_dir = "/jail/";
+    chroot(root_dir);


Warning
Description: We observed that your code exhibits an insecure use of the chroot function, which may lead to security vulnerabilities. We recommend you to ensure that the directory path is secure, proper error handling is implemented, and permissions are appropriately set to prevent unauthorised access. Learn more - https://owasp.org/www-community/vulnerabilities/Least_Privilege_Violation

Severity: High

The fix includes error handling for the chroot call, changes the current working directory to the new root, and adds comments indicating that additional security measures should be implemented. This helps mitigate potential vulnerabilities associated with improper use of chroot.

Suggested change

chroot(root_dir);

// #include <unistd.h>

// #include <errno.h>

// #include <string.h>

// #include <stdio.h>

void noncompliant() {

const char* root_dir = "/jail/";

if (chroot(root_dir) != 0) {

fprintf(stderr, "chroot failed: %s

", strerror(errno));

return;

}

if (chdir("/") != 0) {

fprintf(stderr, "chdir failed: %s

", strerror(errno));

return;

}

// Additional security measures should be implemented here

}

amazon-q-developer · 2025-07-15T13:30:41Z

+#include <stdint.h>
+
+void compliant() {
+    int a = 10;


Warning
Description: We observed that your code contains a dead store, where a variable is assigned a value but never used afterward, which may leads to potential inefficiencies. We recommend you to remove or re-evaluate the variable’s usage to avoid such vulnerabilities. Learn more - https://wiki.sei.cmu.edu/confluence/display/c/MSC13-C.+Detect+and+remove+unused+values

Severity: High

The variable 'a' was removed as it was assigned a value but never used, eliminating the dead store vulnerability. The value 10 is now directly used in the division operation.

Suggested change

int a = 10;

void compliant() {

int b = 0;

if (b != 0) {

// Compliant: Denominator is validated.

int result = 10 / b;

printf("Result: %d

", result);

} else {

printf("Division by zero avoided.

");

amazon-q-developer · 2025-07-15T13:30:42Z

+    int *intPointer = intArray;
+
+    // Noncompliant: Incorrect pointer scaling, multiplying the index by sizeof(int) is redundant.
+    return *(intPointer + (i * sizeof(int)));


Warning
Description: Incorrect pointer scaling in your code can lead to unexpected behavior and security vulnerabilities. To prevent this, ensure that pointer arithmetic is performed correctly by using the appropriate pointer types and allowing the language to handle scaling automatically. Avoid casting pointers to narrower types unnecessarily to maintain correct memory access and avoid potential issues. Learn more - https://cwe.mitre.org/data/definitions/468.html

Severity: High

The fix removes the redundant multiplication by sizeof(int) in the pointer arithmetic. In C, when performing pointer arithmetic, the compiler automatically scales the offset based on the size of the pointed-to type.

Suggested change

return *(intPointer + (i * sizeof(int)));

int intArray[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

int *intPointer = intArray;

// Fixed: Removed redundant multiplication by sizeof(int)

return *(intPointer + i);

}

amazon-q-developer · 2025-07-15T13:30:43Z

+        strncpy(buf, var->myname, sizeof(buf) - 1);
+        buf[sizeof(buf) - 1] = '\0';
+    } else {
+        strcpy(buf, "N/A");


Warning
Description: We observed your code contains an out-of-bounds write which may lead to security issues such as crashing, information leaks, or even arbitrary code execution. You should perform bounds checking, validate input sizes and indices to ensure they stay within the allocated memory bounds. Learn more - https://github.com/harsh-bothra/SecurityExplained/blob/main/resources/cwe-787.md

Severity: High

The vulnerability is fixed by replacing strcpy with strncpy and adding a null terminator to ensure the string is properly bounded within the buffer size, preventing potential buffer overflow.

Suggested change

strcpy(buf, "N/A");

strncpy(buf, var->myname, sizeof(buf) - 1);

buf[sizeof(buf) - 1] = '\0';

} else {

strncpy(buf, "N/A", sizeof(buf) - 1);

buf[sizeof(buf) - 1] = '\0';

}

free(var);

amazon-q-developer · 2025-07-15T13:30:44Z

✅ I finished the code review, and left comments with the issues I found. I will now generate code fix suggestions.

amazon-q-developer · 2025-07-15T13:30:44Z

+    int a = 10;
+    int b = 0;
+    // Noncompliant: Divide-by-zero condition.
+    int result = a / b;


Warning
Description: We observed that flaws related to dividing by zero or performing other arithmetic operations that result in a divide-by-zero condition can lead to unexpected behavior, system crashes, or security vulnerabilities if not properly handled. To prevent these issues, ensure that the denominator is validated. By taking this precaution, you can enhance system stability and security. Learn more - https://www.geeksforgeeks.org/c-program-to-handle-divide-by-zero-and-multiple-exceptions/

Severity: High

The fix adds a conditional check to ensure that the denominator (b) is not zero before performing the division operation. If b is zero, an error message is printed instead of attempting the division.

Suggested change

int result = a / b;

void noncompliant() {

int a = 10;

int b = 0;

// Check for divide-by-zero condition

if (b != 0) {

int result = a / b;

printf("Result: %d

", result);

} else {

printf("Error: Cannot divide by zero

");

}

}

gemini-code-assist

Code Review

This pull request adds a collection of C files intended as test cases for various code detectors. Each detector has corresponding "compliant" and "non-compliant" example files.

My review focused on the correctness and robustness of these test cases. While the files generally demonstrate the intended vulnerabilities or best practices, I found several critical issues in the surrounding mock and helper code. These include returning uninitialized pointers, dereferencing uninitialized pointers, using uninitialized variables, and potential NULL pointer dereferences. Such issues can lead to undefined behavior or crashes, which could interfere with the correct functioning of the detectors these files are meant to test.

I have provided specific suggestions to fix these underlying problems to make the test cases more robust and reliable.

gemini-code-assist · 2025-07-15T13:32:50Z

+    CURL *curl;
+    return curl;


The functions curl_easy_init and curl_easy_init1 declare a local pointer curl but return it without initialization. This leads to undefined behavior for any caller that attempts to use the returned pointer.

CURL* curl_easy_init() { return NULL; } CURL* curl_easy_init1() { return NULL; }

gemini-code-assist · 2025-07-15T13:32:50Z

+    CURLcode *curl;
+    return *curl;


This function declares an uninitialized pointer curl and then dereferences it in the return statement. This will lead to a crash or other undefined behavior when the function is called.

CURLcode my_curl_easy_setopt1(CURL *handle, CURLoption option, const char *url) { return 0; }

gemini-code-assist · 2025-07-15T13:32:50Z

+    printf("Enter username: ");
+
+    // Noncompliant: Using user input without any validation.
+    fgets(username, sizeof(username), stdin);


The sizeof(username) expression is incorrect here. Since username is a pointer (char*), sizeof will return the size of the pointer itself (e.g., 4 or 8 bytes), not the size of the buffer it points to. This is a critical error that can lead to a buffer overflow. You should use the actual buffer size, like MAX_USERNAME.

Suggested change

fgets(username, sizeof(username), stdin);

fgets(username, MAX_USERNAME, stdin);

gemini-code-assist · 2025-07-15T13:32:50Z

+    char *path = getenv("USER_DIR");
+    chdir(path);


The getenv function can return NULL if the specified environment variable is not set. Passing NULL to chdir results in undefined behavior, which typically causes a program crash. You should always check the pointer returned by getenv for NULL before using it.

Suggested change

char *path = getenv("USER_DIR");

chdir(path);

if (path) {

chdir(path);

}

gemini-code-assist · 2025-07-15T13:32:50Z

+int compliant() {
+    NAME *var;
+    char buf[10];
+    var = (NAME *)malloc(sizeof(struct name));


Memory is allocated for var using malloc, but the memory is not initialized. This means var->myname contains an indeterminate pointer value. Accessing this pointer on line 30 results in undefined behavior and will likely crash the program. To fix this, you can use calloc to allocate and zero-initialize the memory, which ensures var->myname will be NULL.

Suggested change

var = (NAME *)malloc(sizeof(struct name));

var = (NAME *)calloc(1, sizeof(struct name));

gemini-code-assist · 2025-07-15T13:32:50Z

+
+int bad()
+{
+    unsigned short uvar;


The variable uvar is used in the comparison on line 13 without being initialized. This results in undefined behavior. While the uvar < 0 check is the intended non-compliant pattern, using an uninitialized variable is a separate and critical bug.

Suggested change

unsigned short uvar;

unsigned short uvar = 0;

gemini-code-assist · 2025-07-15T13:32:50Z

+void create_file(username)
+{
+}


This function is defined using an old K&R C style where the parameter type is missing. The type for username defaults to int, but the function is called with a char* on line 19. This type mismatch can lead to undefined behavior. Please specify the type explicitly.

Suggested change

void create_file(username)

{

}

void create_file(char *username)

{

}

gemini-code-assist · 2025-07-15T13:32:51Z

+#define X509_V_OK 1
+#define X509_V_ERR_CERT_HAS_EXPIRED 1


The macros X509_V_OK and X509_V_ERR_CERT_HAS_EXPIRED are both defined with the same value 1. This makes the verification check result != X509_V_OK on line 33 ineffective, as it would fail to detect an expired certificate error. These macros should have distinct values. In OpenSSL, X509_V_OK is typically 0.

#define X509_V_OK 0 #define X509_V_ERR_CERT_HAS_EXPIRED 1

gemini-code-assist · 2025-07-15T13:32:51Z

+#define X509_V_OK 1
+#define X509_V_ERR_CERT_HAS_EXPIRED 1


The macros X509_V_OK and X509_V_ERR_CERT_HAS_EXPIRED are both defined with the same value 1. While this non-compliant example doesn't perform verification, using identical values for success and error conditions is misleading and incorrect for a test setup. In OpenSSL, X509_V_OK is typically 0.

#define X509_V_OK 0 #define X509_V_ERR_CERT_HAS_EXPIRED 1

gemini-code-assist · 2025-07-15T13:32:51Z

+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: MIT-0
+
+// {fact rule=c-cpp-incorrect-pointer-scaling@v1.0 defects=1}


The defects count in the {fact} comment is set to 1. For a compliant code example, this should be 0.

Suggested change

// {fact rule=c-cpp-incorrect-pointer-scaling@v1.0 defects=1}

// {fact rule=c-cpp-incorrect-pointer-scaling@v1.0 defects=0}

branedev2 · 2025-10-01T15:49:26Z

@CodeRabbit review

coderabbitai · 2025-10-01T15:49:33Z

✅ Actions performed

Review triggered.

Note: CodeRabbit is an incremental review system and does not re-review already reviewed commits. This command is applicable only when automatic reviews are paused.

branedev2 · 2025-10-01T15:50:39Z

@CodeRabbit review

branedev2 · 2025-10-01T15:52:47Z

@coderabbitai review

Add PR_3_cpp detector files

e380d0b

gemini-code-assist Bot reviewed Jul 15, 2025

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amazon-q-developer Bot reviewed Jul 15, 2025

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gemini-code-assist Bot reviewed Jul 15, 2025

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-    chroot(root_dir);
+// #include <unistd.h>
+// #include <errno.h>
+// #include <string.h>
+// #include <stdio.h>
+void noncompliant() {
+    const char* root_dir = "/jail/";
+    if (chroot(root_dir) != 0) {
+        fprintf(stderr, "chroot failed: %s
+", strerror(errno));
+        return;
+    }
+    if (chdir("/") != 0) {
+        fprintf(stderr, "chdir failed: %s
+", strerror(errno));
+        return;
+    }
+    // Additional security measures should be implemented here
+}

-    int a = 10;
+void compliant() {
+    int b = 0;
+    if (b != 0) {
+        // Compliant: Denominator is validated.
+        int result = 10 / b;
+        printf("Result: %d
+", result);
+    } else {
+        printf("Division by zero avoided.
+");

-    return *(intPointer + (i * sizeof(int)));
+int intArray[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    int *intPointer = intArray;
+    // Fixed: Removed redundant multiplication by sizeof(int)
+    return *(intPointer + i);
+}

	fgets(username, sizeof(username), stdin);
	fgets(username, MAX_USERNAME, stdin);

	var = (NAME *)malloc(sizeof(struct name));
	var = (NAME *)calloc(1, sizeof(struct name));

	// {fact rule=c-cpp-incorrect-pointer-scaling@v1.0 defects=1}
	// {fact rule=c-cpp-incorrect-pointer-scaling@v1.0 defects=0}

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