CVE-2025-53737 in Excel
Summary
by MITRE • 08/12/2025
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/16/2025
The vulnerability identified as CVE-2025-53737 represents a critical heap-based buffer overflow flaw within Microsoft Office Excel software. This vulnerability resides in the application's handling of malformed or specially crafted spreadsheet files, specifically affecting how Excel processes certain data structures during file parsing operations. The buffer overflow occurs when Excel attempts to write data beyond the allocated memory boundaries in heap memory regions, creating a condition where attacker-controlled data can overwrite adjacent memory locations. Such vulnerabilities are particularly dangerous because they can be exploited to execute arbitrary code with the privileges of the targeted user, making them prime targets for exploitation in targeted attacks.
The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows data to be written beyond allocated heap memory regions. The flaw manifests when Excel encounters specially crafted spreadsheet files containing malformed data structures that trigger improper memory allocation and handling. Attackers can construct malicious excel files that, when opened by an unsuspecting user, cause the application to allocate insufficient memory for processing the data, leading to overflow conditions that can be leveraged for code execution. The vulnerability is particularly concerning because it requires no special privileges to exploit, as it operates within the context of a standard user session, making it accessible to adversaries who can only rely on social engineering or other non-privileged attack vectors.
The operational impact of CVE-2025-53737 extends beyond simple local code execution, as it provides attackers with a potential foothold for more sophisticated attacks within corporate networks. When an attacker successfully exploits this vulnerability, they can execute malicious code that may escalate privileges, establish persistence mechanisms, or even deploy additional malware payloads. The vulnerability's exploitation typically occurs through spear-phishing campaigns where users receive malicious excel files via email, or through compromised websites that deliver malicious content. According to ATT&CK framework, this vulnerability maps to techniques such as T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, demonstrating how a single vulnerability can enable multiple attack vectors. The risk is amplified by the widespread use of Microsoft Office across enterprise environments, making successful exploitation potentially devastating for organizations that lack proper security controls.
Mitigation strategies for CVE-2025-53737 should focus on both immediate defensive measures and long-term security enhancements. Microsoft has released security updates addressing this vulnerability, and organizations should prioritize applying these patches immediately to protect their systems. In the interim period before patching, administrators should implement additional security controls such as restricting user permissions when opening office files, implementing application control policies that limit execution of potentially malicious files, and deploying email filtering solutions that can detect and block suspicious excel attachments. Network-based defenses including intrusion detection systems and web proxies can help identify and prevent exploitation attempts. Organizations should also consider implementing user education programs to reduce the risk of successful social engineering attacks that rely on this vulnerability. Security monitoring should focus on detecting anomalous behavior patterns that may indicate exploitation attempts, particularly around file execution and memory allocation patterns. The vulnerability highlights the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies that reduce the attack surface and limit the impact of successful exploits.