CVE-2015-0537 in BSAFE Crypto-C
Summary
by MITRE
Integer underflow in the base64-decoding implementation in EMC RSA BSAFE Micro Edition Suite (MES) 4.0.x before 4.0.8 and 4.1.x before 4.1.3, RSA BSAFE Crypto-C Micro Edition (Crypto-C ME) before 4.0.4 and 4.1, and RSA BSAFE SSL-C 2.8.9 and earlier allows remote attackers to cause a denial of service (memory corruption or segmentation fault) or possibly have unspecified other impact via crafted base64 data, a similar issue to CVE-2015-0292.
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Analysis
by VulDB Data Team • 06/12/2022
The vulnerability identified as CVE-2015-0537 represents a critical integer underflow flaw within the base64-decoding implementations of several RSA BSAFE cryptographic libraries. This issue affects multiple versions of the RSA BSAFE Micro Edition Suite including MES 4.0.x before 4.0.8 and 4.1.x before 4.1.3, as well as RSA BSAFE Crypto-C Micro Edition versions prior to 4.0.4 and 4.1, and RSA BSAFE SSL-C 2.8.9 and earlier. The flaw manifests when processing crafted base64 data that triggers an integer underflow condition during the decoding process, creating a dangerous scenario where the application's memory management becomes compromised.
The technical exploitation of this vulnerability occurs through the manipulation of base64-encoded data that causes arithmetic overflow conditions in the integer variables used for buffer size calculations. When the base64 decoding routine encounters malformed input, the integer underflow results in incorrect buffer allocation sizes, leading to memory corruption patterns that can manifest as segmentation faults or more subtle memory corruption issues. This type of vulnerability falls under the CWE-191 category of Integer Underflow (Wrap or Wraparound) and demonstrates the classic pattern of arithmetic operations that fail to properly validate input boundaries. The underlying issue stems from insufficient validation of input data length and improper handling of integer arithmetic in the decoding algorithms, creating a pathway for attackers to manipulate the program's memory layout through carefully crafted malicious input sequences.
From an operational impact perspective, this vulnerability presents significant risks to systems utilizing the affected RSA BSAFE libraries, particularly those implementing secure communications protocols that rely on base64 encoding for data transmission. The potential for remote code execution cannot be ruled out, as the memory corruption could be leveraged to achieve arbitrary code execution, while the more likely immediate impact involves denial of service conditions that can crash applications or services. The vulnerability's similarity to CVE-2015-0292 indicates a broader pattern of integer overflow/underflow issues within the RSA BSAFE cryptographic implementations, suggesting that developers may have overlooked fundamental input validation mechanisms in their cryptographic libraries. Organizations using these libraries in mission-critical applications face potential service disruption, data integrity issues, and increased attack surface for sophisticated adversaries who might exploit this weakness to gain unauthorized access or cause system instability.
The mitigation strategy for CVE-2015-0537 requires immediate patching of all affected RSA BSAFE library versions to their latest secure releases, with particular attention to the specific version numbers mentioned in the vulnerability description. System administrators should conduct comprehensive inventory audits to identify all instances of the affected libraries across their infrastructure, as the vulnerability affects multiple products within the RSA BSAFE ecosystem. Network monitoring should be enhanced to detect potential exploitation attempts through anomalous base64 data patterns, and input validation should be strengthened at all application layers that process base64-encoded data. The vulnerability aligns with ATT&CK techniques related to privilege escalation and denial of service through memory corruption, making it particularly relevant for organizations implementing security frameworks that consider both defensive and offensive threat modeling approaches. Additionally, organizations should consider implementing runtime protections such as address space layout randomization and stack canaries to provide additional defense-in-depth measures against potential exploitation attempts.