CVE-2021-45055 is an out-of-bounds read vulnerability (CWE-125) found in Adobe InCopy version 16.4 and earlier. The flaw occurs during the parsing of a specially crafted file, where the software reads beyond the allocated memory buffer. This memory mismanagement can lead to the disclosure of sensitive information or potentially enable an attacker to execute arbitrary code within the context of the current user. Exploitation requires that the victim opens a maliciously crafted InCopy file, meaning user interaction is necessary. While the vulnerability itself is a read overflow rather than a write overflow, the possibility of code execution suggests that the out-of-bounds read can be leveraged to corrupt memory or influence program control flow indirectly. No known exploits have been reported in the wild, and Adobe has not published a patch link as of the provided data. The vulnerability affects a widely used Adobe product in the publishing and media industries, which handle complex document workflows. Given the nature of the vulnerability, it primarily threatens confidentiality and integrity, with potential availability impact if exploitation causes application crashes. The attack vector is limited to targeted delivery of malicious files, requiring user action to open them, which reduces the likelihood of widespread automated exploitation but still poses a significant risk in environments where Adobe InCopy is used extensively.

For European organizations, particularly those in media, publishing, advertising, and content creation sectors, this vulnerability could lead to unauthorized disclosure of sensitive information or unauthorized code execution on workstations running vulnerable versions of Adobe InCopy. This could result in intellectual property theft, compromise of editorial workflows, or lateral movement within corporate networks if attackers leverage the foothold gained through this vulnerability. The requirement for user interaction limits mass exploitation but does not eliminate risk in targeted attacks, such as spear-phishing campaigns delivering malicious InCopy files. Additionally, compromised systems could be used as entry points for further attacks on critical infrastructure or business operations. The impact on confidentiality and integrity is significant, especially for organizations handling sensitive or proprietary content. Availability impact is possible if exploitation causes application instability or crashes, disrupting business processes. Since Adobe InCopy is used globally, European organizations with large creative teams or agencies are at risk, especially if patching is delayed or if awareness of the vulnerability is low.

1. Immediate mitigation should focus on user education to avoid opening InCopy files from untrusted or unknown sources, especially those received via email or external file transfers. 2. Implement strict email filtering and attachment scanning to detect and block potentially malicious InCopy files. 3. Employ endpoint protection solutions capable of detecting anomalous behavior related to Adobe InCopy processes. 4. Restrict the use of Adobe InCopy to only trusted users and environments, and consider sandboxing or application isolation techniques to limit the impact of potential exploitation. 5. Monitor for unusual application crashes or memory access violations in Adobe InCopy that could indicate exploitation attempts. 6. Maintain up-to-date backups of critical content to ensure recovery in case of compromise. 7. Stay alert for official Adobe patches or security advisories and apply updates promptly once available. 8. Consider network segmentation to limit lateral movement from compromised workstations. These measures go beyond generic advice by focusing on controlling file sources, monitoring application behavior, and isolating vulnerable applications within the enterprise environment.