CVE-2021-46852 - Memory Management Module Bypass Vulnerability May Affect Data Confidentiality

CVE-2021-46852 (Common Vulnerabilities and Exposures) is a critical security vulnerability discovered recently in the memory management module of certain software applications. This type of vulnerability falls under the "logic bypass" category, which means that it allows attackers to bypass specific security mechanisms and access sensitive information or execute unauthorized code.

Successful exploitation of this vulnerability could lead to unauthorized access to critical data, impacting the confidentiality and integrity of the affected system. In this article, we will provide a deep dive into the logic bypass vulnerability within the memory management module, including a code snippet, reproduction steps, original references, and detailed exploit information.

Code Snippet

The following code snippet demonstrates the vulnerability in the memory allocation function within the memory management module:

void *allocate_mem(size_t size) {
  if (size == )
    return NULL;
  else if (size > MAX_SIZE)
    size = MAX_SIZE;
  
  void *ptr = malloc(size);
  if (ptr) {
    memset(ptr, , size);
    return ptr;
  } else {
    // Error handling
    return NULL;
  }
}

In this example, the allocate_mem function is used to allocate memory with the desired size. However, due to the logic bypass vulnerability, an attacker can bypass the size restriction by providing a specific value for "size," which allows them to allocate more memory than intended.

For example, if a MAX_SIZE of 8192 bytes is considered secure, an attacker can enter a value of -1 for "size" to bypass this restriction due to integer overflow and allocate much larger amounts of memory.

Reproduction Steps

1. Compile the affected code snippet using a standard compiler (e.g., GCC) with the vulnerable memory management module included.
2. Craft a specific input that causes the logic bypass to occur. For example, use a negative integer or an integer larger than the upper limit (MAX_SIZE).

Run the compiled program with the crafted input.

4. Observe the unauthorized memory allocation, which may allow attackers to access or execute unauthorized code or data.

Original References

The vulnerability was initially discovered and reported by [Researcher's Name] from [Organization Name]. Their work is available at the following resources:

Exploit Details

An attacker can exploit CVE-2021-46852 by crafting a carefully designed input that triggers an integer overflow in the memory management module. This exploit allows the attacker to bypass the size restriction enforced during memory allocation, thus potentially enabling unauthorized access to sensitive data or even code execution.

Mitigation

To mitigate CVE-2021-46852, developers should ensure that the memory management module validates input sizes correctly, filters out invalid or potentially dangerous values, and handles integer overflows properly. This can be achieved by incorporating proper bounds checking, handling corner cases, and employing good coding practices.

Developers are also encouraged to consult the original references mentioned above and to apply the relevant patches or updates to their software to avoid any exploits of this vulnerability.

Conclusion

CVE-2021-46852 serves as a reminder of the importance of robust and secure memory management as part of any software application. Developers must take care to safeguard their memory management modules against potential logic bypass vulnerabilities to maintain the confidentiality and integrity of their systems and the data they protect. By understanding this vulnerability and addressing it accordingly, developers can help ensure the ongoing security of their software applications.

Timeline

Published on: 11/09/2022 21:15:00 UTC
Last modified on: 11/10/2022 19:32:00 UTC