CVE-2011-0188 in Ruby
Summary
by MITRE
The VpMemAlloc function in bigdecimal.c in the BigDecimal class in Ruby 1.9.2-p136 and earlier, as used on Apple Mac OS X before 10.6.7 and other platforms, does not properly allocate memory, which allows context-dependent attackers to execute arbitrary code or cause a denial of service (application crash) via vectors involving creation of a large BigDecimal value within a 64-bit process, related to an "integer truncation issue."
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/03/2024
The vulnerability described in CVE-2011-0188 represents a critical memory allocation flaw within Ruby's BigDecimal implementation that specifically affects systems running Ruby 1.9.2-p136 and earlier versions. This issue manifests in the VpMemAlloc function located in bigdecimal.c, which is responsible for managing memory allocation during BigDecimal object creation. The vulnerability occurs when processing large BigDecimal values within 64-bit processes, creating a scenario where memory allocation calculations become corrupted due to improper handling of integer values. The flaw is particularly dangerous because it can be exploited to execute arbitrary code or cause application crashes, making it a significant security concern for systems that rely on Ruby's BigDecimal functionality for financial calculations or precise numerical operations.
The technical root cause of this vulnerability stems from an integer truncation issue that occurs during memory allocation calculations. When the BigDecimal class processes exceptionally large numerical values, the VpMemAlloc function fails to properly handle the conversion of large integer values to smaller data types during memory allocation calculations. This truncation results in insufficient memory being allocated for the actual data structure, creating a buffer that is too small to accommodate the intended data. The vulnerability is specifically context-dependent, meaning that attackers must be able to influence the creation of large BigDecimal values within a 64-bit process environment to exploit it successfully. This characteristic makes the vulnerability somewhat more difficult to trigger remotely but still highly dangerous when an attacker can control input data that gets processed through Ruby's BigDecimal functions.
The operational impact of CVE-2011-0188 extends beyond simple denial of service scenarios to encompass full arbitrary code execution capabilities, making it a severe security risk for affected systems. When exploited, this vulnerability can allow attackers to execute malicious code with the privileges of the affected application, potentially leading to complete system compromise. The vulnerability affects not only Apple Mac OS X systems before version 10.6.7 but also other platforms running vulnerable versions of Ruby, creating a widespread attack surface. Applications that process user-supplied numerical data through Ruby's BigDecimal class are particularly at risk, including financial applications, scientific computing tools, and any system that performs precise decimal arithmetic operations. The vulnerability's impact is exacerbated by the fact that it can be triggered through normal application usage patterns, making detection and prevention challenging for system administrators.
Mitigation strategies for CVE-2011-0188 should prioritize immediate patching of affected Ruby installations to versions that contain the necessary memory allocation fixes. System administrators should implement input validation controls that limit the size and complexity of BigDecimal values processed by applications, particularly those handling user input. The vulnerability aligns with CWE-190, which describes integer overflow and unsigned integer wraparound issues, and can be mapped to ATT&CK technique T1059.007 for script-based attacks where attackers leverage application flaws to execute malicious code. Organizations should also consider implementing monitoring solutions that detect unusual BigDecimal processing patterns and establish secure coding practices that prevent the exploitation of integer truncation vulnerabilities. Additionally, network segmentation and application firewalls can help limit the potential impact of successful exploitation attempts, while regular security assessments should verify that all Ruby installations are updated to patched versions that address this specific memory allocation flaw.