CVE-2025-2020 in Cobalt
Summary
by MITRE • 03/11/2025
Ashlar-Vellum Cobalt VC6 File Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Ashlar-Vellum Cobalt. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the parsing of VC6 files. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-25254.
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Analysis
by VulDB Data Team • 08/08/2025
This vulnerability resides in the Ashlar-Vellum Cobalt software's handling of VC6 file format parsing, representing a critical out-of-bounds write condition that can be exploited remotely. The flaw manifests when the application processes maliciously crafted VC6 files without adequate input validation, creating a scenario where attacker-controlled data can overwrite memory beyond the intended buffer boundaries. This type of vulnerability falls under CWE-787: "Out-of-bounds Write" and represents a fundamental failure in memory safety controls that directly enables arbitrary code execution capabilities. The vulnerability is particularly concerning because it requires only user interaction through visiting a malicious webpage or opening a compromised file, making it highly exploitable in real-world scenarios.
The technical implementation of this vulnerability stems from insufficient bounds checking during VC6 file parsing operations. When the application encounters a malformed VC6 file, it fails to validate the size and structure of incoming data before attempting memory allocation and subsequent write operations. This lack of proper input sanitization creates a predictable memory corruption scenario where an attacker can craft specific file contents that will cause the application to write data beyond allocated memory regions. The vulnerability operates at the application level within the Cobalt software's file processing pipeline, where the buffer overflow can be manipulated to overwrite critical memory structures including return addresses or function pointers, ultimately allowing code execution in the context of the current process. This aligns with ATT&CK technique T1203: "Exploitation for Client Execution" and demonstrates how file format vulnerabilities can be leveraged for remote code execution.
The operational impact of this vulnerability extends beyond simple code execution to potentially enable full system compromise when combined with other exploitation techniques. Attackers can leverage this vulnerability to establish persistent access, escalate privileges, or deploy additional malicious payloads within the victim's environment. The requirement for user interaction through web browsing or file opening makes this vulnerability particularly dangerous in phishing campaigns or social engineering attacks where users may be诱导ed to interact with malicious content. Organizations running Ashlar-Vellum Cobalt software are at risk of unauthorized access, data breaches, and potential lateral movement within their networks if this vulnerability is not addressed promptly. The vulnerability's classification as a remote code execution flaw means that attackers do not require physical access to systems or network proximity to exploit the weakness, making it a significant threat to enterprise security postures.
Mitigation strategies should focus on immediate software updates from Ashlar-Vellum to address the buffer overflow condition in VC6 file parsing. Organizations should implement network-based protections such as web application firewalls and content filtering systems to block access to known malicious domains hosting exploit content. Additionally, user education and awareness programs should emphasize the dangers of opening unknown files or visiting untrusted websites that may contain malicious VC6 files. System hardening measures including address space layout randomization and data execution prevention should be enabled to make exploitation more difficult. Security teams should monitor for indicators of compromise related to this vulnerability and implement proper incident response procedures for potential exploitation attempts. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in other software applications within the organization's environment, following established security frameworks such as NIST SP 800-53 controls for vulnerability management and risk mitigation.