Description

A user able to submit SQL through an application using the MongoDB Connector for BI ODBC driver can supply a positioned-cursor statement whose cursor name exceeds the size of an internal fixed-length buffer. Because the name length is not bounded before the driver builds its diagnostic message, memory adjacent to that buffer is overwritten with user-supplied content. This can terminate the hosting application process and may allow unintended code to run within it.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-28T22:16:54.793Z",
  "pubdate": "2026-08-28T22:16:54.793Z",
  "executiveSummary": "The MongoDB Connector for BI ODBC driver contains a buffer overflow vulnerability resulting from inadequate input validation when processing positioned-cursor SQL statements.\nThis vulnerability is classified as a memory corruption flaw, which can be exploited by an authenticated attacker to trigger application termination or achieve arbitrary code execution within the context of the hosting process.\nThe flaw exists because the driver fails to enforce length constraints on cursor names before incorporating them into internal diagnostic messages.\nSuccessful exploitation poses a critical risk to systems utilizing the BI connector, as it bypasses standard memory safety boundaries, potentially leading to unauthorized system control or denial-of-service conditions.\nThe impact is dependent on the attacker's ability to supply malformed SQL input directly to the application interface, making this a high-severity concern for any environment where database interactions are influenced by external user input.",
  "technicalDetails": "The vulnerability resides within the MongoDB Connector for BI ODBC driver's handling of positioned-cursor SQL statements. The root cause is a classic stack-based or heap-based buffer overflow triggered by an unchecked copy operation into a fixed-length internal buffer.\nWhen an application processes a SQL statement involving a cursor, the driver is responsible for parsing the cursor name. During the construction of diagnostic or error messages, the driver attempts to store the user-provided cursor name into a pre-allocated, fixed-size memory buffer. However, the implementation lacks a validation check to verify that the length of the supplied cursor name does not exceed the capacity of the target buffer.\nThe attack flow begins when an attacker, possessing the ability to submit arbitrary SQL queries through an application interface, provides a crafted positioned-cursor statement. The cursor name within this statement is intentionally crafted to exceed the size of the internal buffer. As the driver processes this string to generate diagnostic output, it performs an unchecked memory copy (e.g., using functions similar to strcpy or memcpy without size constraints).\nBecause the buffer is fixed-length, the excess data overflows into adjacent memory regions. This overflow allows for the corruption of adjacent control structures, function pointers, or return addresses on the stack. If an attacker carefully crafts the payload within the cursor name, they can overwrite these pointers to redirect the instruction pointer (EIP/RIP) to attacker-controlled shellcode or execute return-oriented programming (ROP) chains.\nThe impact of this exploitation is multifaceted. At a minimum, the corruption of adjacent memory leads to a segmentation fault or memory access violation, causing an immediate denial-of-service (DoS) as the host application process crashes. In more sophisticated scenarios, the ability to control the execution flow allows for arbitrary code execution, granting the attacker the same privileges as the user or service account running the ODBC-enabled application.\nThis vulnerability is particularly dangerous because it occurs within the driver layer, which often operates with high privileges within the application stack. Authentication requirements are effectively bypassed if the application allows user-supplied SQL strings, and the attack does not necessarily require complex network-level exploitation techniques, as it relies on legitimate, albeit malformed, query inputs."
}