CVE-2021-44490 in YottaDB
Summary
by MITRE • 04/15/2022
An issue was discovered in YottaDB through r1.32 and V7.0-000. Using crafted input, attackers can cause a calculation of the size of calls to memset in op_fnj3 in sr_port/op_fnj3.c to result in an extremely large value in order to cause a segmentation fault and crash the application. This is a "- (digs < 1 ? 1 : digs)" subtraction.
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Analysis
by VulDB Data Team • 04/21/2022
The vulnerability identified as CVE-2021-44490 represents a critical memory management flaw within the YottaDB database system, specifically affecting versions through r1.32 and V7.0-000. This issue manifests in the sr_port/op_fnj3.c source file where the op_fnj3 function processes certain input parameters that ultimately lead to a malformed memory allocation calculation. The flaw stems from a mathematical operation involving the subtraction of a conditional expression that directly influences how the memset function calculates memory boundaries during execution. When attackers provide carefully crafted input data, the calculation logic produces an unexpectedly large integer value that subsequently causes the application to attempt to allocate an enormous amount of memory, leading to a segmentation fault and complete application crash.
The technical root cause of this vulnerability can be traced to a specific code pattern that computes memory requirements for string operations within the database engine's function processing routines. The problematic calculation involves a subtraction operation where "digs < 1 ? 1 : digs" serves as the operand being subtracted from a base value, creating an arithmetic condition that can result in extreme numerical overflow when the input parameter "digs" falls below the expected range. This type of vulnerability falls under the CWE-190 category of Integer Overflow or Wraparound, specifically manifesting as a memory allocation error that can be exploited to cause denial of service through controlled application termination. The flaw demonstrates poor input validation and inadequate boundary checking in memory management calculations, which represents a fundamental weakness in the software's defensive programming practices.
The operational impact of CVE-2021-44490 extends beyond simple application instability to potentially enable more sophisticated attack vectors within database environments. Since YottaDB serves as a high-performance database system commonly used in mission-critical applications, this vulnerability could be exploited to disrupt database services, causing significant downtime and potential data access interruptions. Attackers could leverage this flaw to repeatedly crash database processes, effectively creating a denial of service condition that would prevent legitimate users from accessing database resources. The vulnerability's exploitation requires minimal input crafting skills and can be automated, making it particularly dangerous in environments where database availability is paramount for business operations. This type of flaw also represents a potential pathway for attackers to establish persistence or to conduct more complex attacks by first destabilizing the target system.
Mitigation strategies for CVE-2021-44490 should prioritize immediate patching of affected YottaDB versions to the latest stable releases that contain the corrected memory calculation logic. Organizations should implement input validation measures at the application level to filter out potentially malicious data patterns that could trigger the vulnerable code path. Network-level protections including firewall rules and intrusion detection systems can help identify and block suspicious input patterns that may exploit this vulnerability. The ATT&CK framework categorizes this type of vulnerability under T1499.004 - Endpoint Denial of Service, emphasizing the need for comprehensive defensive measures. Additionally, system administrators should monitor for unusual memory allocation patterns and segmentation fault occurrences that may indicate exploitation attempts. Regular security assessments and code reviews focusing on memory management calculations should be implemented to prevent similar issues in other components of the database infrastructure. The vulnerability serves as a reminder of the critical importance of proper integer handling and boundary validation in security-critical systems, particularly those handling user-provided input in memory-intensive operations.