# Unveiling the Landscape of Operating System Vulnerabilities
## 5 Findings and Discussion
### CWE-120  
This is the case of buffer overflow, where attackers can exploit the system by deliberately inputting more data into a program or system than it can handle.  
\begin{table}
\begin{tabular}{l l l} \hline \hline
**CWE ID** & **Count** & **Description** \\ \hline CWE-787 & 3945 & Out-of-bounds Write \\ CWE-119 & 3802 & Improper Restriction of Operations within the Bounds of a Memory Buffer \\ CWE-20 & 3365 & Improper Input Validation \\ CWE-200 & 2199 & Exposure of Sensitive Information to an Unauthorized Actor \\ CWE-125 & 2105 & Out-of-bounds Read \\ CWE-79 & 1707 & Cross-site Scripting \\ CWE-416 & 1568 & Use After Free \\ CWE-264 & 1508 & Permissions, Privileges, and Access Controls \\ CWE-78 & 1208 & OS Command Injection \\ CWE-120 & 1107 & Classic Buffer Overflow \\ \hline \hline \end{tabular}
\end{table}
Table 5: Top 10 vulnerability types across all OSs with their CWE IDs, overall count, and description.  
Figure 9 shows the year-wise count of each vulnerability type in our top 10 list. We present the following observations from the figure:  
* There is no significant occurrence of CWE-787 until 2017 (200 instances), but rapid growth is seen in CWE-787 starting in 2018 with the all-time high among all vulnerability types in 2022 (1155 instances). This trend serves as an indicator that OS are encountering an increasing prevalence of out-of-bounds write vulnerabilities every year, and requires immediate attention to this vulnerability type.
* CWE-119 was seen maximize at 774 in 2017; however, by 2022, this figure decreased to a mere 78 instances. This indicates that the OSs are made to be robust, with proper restriction of operations within the bounds of the memory buffer.
* CWE-200 was at its maximum in 2017 (548 instances); however, the figure reduced greatly, with only 55 instances observed in 2022. This indicates that OSs have become alert and strict about the exposure of sensitive information to unauthorized parties.
* The highest number of instances of CWE-264, totaling 453, was recorded in 2016. Surprisingly, this vulnerability exhibited a sharp decline in subsequent years, with no observations reported from 2020 to 2022. This reduction in reported CWE-264 indicates enhancement of security measures and stricter access controls, or in other words, we can say the potential vulnerabilities regarding Permissions, Privileges, and Access Controls have been adequately addressed.
* The rest of the vulnerability types exhibit consistent observations each year.  
We expanded our analysis by identifying the common vulnerability types observed in our top 10 vulnerable OS categories. The findings reveal four common vulnerabilities: CWE-119, CWE-787, CWE-20, and CWE-200. Table 6 presents the count of these vulnerability types for each OS category in our top 10 list. It is noteworthy that these four vulnerabilities consistently impacted these OSs from the early 2000s to 2022, as shown by Figure 9. Furthermore, Table 7 demonstrates the most observed CWE weaknesses in our top 10 vulnerable OS versions in recent years, i.e., 2021-2022. We can observe that Windows 10 and Windows 11 are highly vulnerable to CWE-269. The CWE-269 refers to \"Improper Privilege Management\", i.e., the product does not assign, check, or track the privileges for the actor. Furthermore, CWE-787 is mostly prevalent in Android versions 11 and 12 and Debian Linux versions 10 and 11 in recent years. Similarly, Windows Server 2012,  
Figure 9: Year-wise observation of the top 10 vulnerability types (CWE IDs).  
Fedora 37, Android 13, and HarmonyOS 2 mostly exhibit CWE-200, CWE-416, CWE-862, and CWE-125, respectively.  
These findings highlight the common vulnerability types observed across our top 10 vulnerable OS versions. By identifying these vulnerabilities, users and organizations can better understand the prevailing security risks and take appropriate measures to mitigate them. It is highly recommended that the corresponding vendors closely monitor the potential occurrence of these vulnerabilities.