CVE-2025-53783 in Teams
Summary
by MITRE • 08/12/2025
Heap-based buffer overflow in Microsoft Teams allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 09/03/2025
The heap-based buffer overflow vulnerability identified as CVE-2025-53783 resides within Microsoft Teams software, presenting a critical security risk that enables remote code execution by unauthorized attackers. This vulnerability specifically targets the heap memory management mechanisms employed by the application, creating a condition where attacker-controlled data can overwrite adjacent memory locations in the heap allocation space. The flaw manifests when the application processes certain input data structures without proper bounds checking, allowing malicious payloads to overflow allocated memory buffers and potentially overwrite critical program execution pointers or return addresses.
The technical exploitation of this vulnerability follows established patterns of heap overflow attacks that align with common weakness enumerations such as CWE-121, which describes heap-based buffer overflow conditions. Attackers can leverage this vulnerability by crafting malicious network requests or data inputs that trigger the vulnerable code path within Microsoft Teams. The heap overflow occurs during normal application processing when user-supplied data is improperly validated before being copied into heap-allocated buffers, enabling attackers to manipulate memory contents and redirect execution flow. This type of vulnerability is particularly dangerous because it operates at the memory management level, allowing for sophisticated exploitation techniques including return-oriented programming and stack pivoting.
The operational impact of CVE-2025-53783 extends beyond simple remote code execution to encompass potential system compromise and data exfiltration capabilities. Once successfully exploited, attackers can gain full control over affected Microsoft Teams installations, potentially accessing sensitive communications, files, and system resources. The vulnerability affects Microsoft Teams clients across multiple platforms including desktop and mobile applications, making it a widespread concern for organizations relying on the platform for business communications. The network-based nature of the exploit means that attackers do not require local system access or physical presence, enabling remote attacks from any location with network connectivity to the target system.
Organizations should implement immediate mitigations including applying the latest Microsoft security patches and updates as soon as they become available through standard Microsoft update channels. Network segmentation and firewall rules can help limit exposure by restricting access to Microsoft Teams services only to authorized users and systems. Additionally, monitoring network traffic for suspicious patterns and implementing intrusion detection systems can help identify potential exploitation attempts. Security teams should also conduct thorough vulnerability assessments to identify all instances of Microsoft Teams installations within their environments and ensure proper patch management procedures are in place. The ATT&CK framework categorizes this vulnerability under technique T1203, which involves exploiting software vulnerabilities for remote code execution, emphasizing the need for comprehensive defensive measures including endpoint protection, network monitoring, and regular security assessments to prevent successful exploitation attempts.