CVE-2021-21050 in Photoshop
Summary
by MITRE • 02/12/2021
Adobe Photoshop versions 21.2.4 (and earlier) and 22.1.1 (and earlier) are affected by an Out-of-bounds Read vulnerability when parsing a specially crafted file. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
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Analysis
by VulDB Data Team • 02/28/2021
Adobe Photoshop contains a critical out-of-bounds read vulnerability in its file parsing mechanism that affects versions 21.2.4 and earlier, as well as 22.1.1 and earlier. This vulnerability resides in the application's handling of specially crafted files during the parsing process, where insufficient bounds checking allows an attacker to read memory locations beyond the intended buffer boundaries. The flaw manifests when Photoshop attempts to process malformed input data, specifically within the image file interpretation routines that do not properly validate the size or structure of incoming data segments. This technical deficiency creates a pathway for memory corruption that can be exploited to execute arbitrary code with the privileges of the currently logged-in user.
The operational impact of this vulnerability extends beyond simple code execution, as it represents a significant escalation from a mere memory access issue to a full remote code execution capability. Attackers can craft malicious image files that, when opened by an unsuspecting user, trigger the out-of-bounds read condition and subsequently overwrite critical memory locations with malicious instructions. The vulnerability requires user interaction for exploitation, meaning victims must manually open the crafted file, but this requirement does not significantly reduce the risk given the prevalence of image file attachments in email communications and web browsing activities. This attack vector aligns with common social engineering techniques where users are tricked into opening seemingly legitimate image files.
From a cybersecurity perspective, this vulnerability maps directly to CWE-125 Out-of-bounds Read within the Common Weakness Enumeration framework, specifically demonstrating how inadequate input validation can lead to memory corruption vulnerabilities. The attack pattern follows typical exploitation methodologies described in the MITRE ATT&CK framework under technique T1059 Command and Scripting Interpreter and T1203 Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute malicious code. The privilege escalation aspect of this vulnerability means that successful exploitation could allow attackers to gain persistent access to systems, potentially leading to full system compromise. Organizations should consider this vulnerability as a high-priority threat given its potential for remote code execution and the widespread use of Photoshop in creative and professional environments.
The recommended mitigation strategy involves immediate patching of affected Adobe Photoshop installations to the latest versions that contain the necessary security fixes. System administrators should implement comprehensive software update policies that ensure all user-facing applications remain current with security patches. Additionally, organizations should deploy application whitelisting controls to restrict execution of unauthorized software and implement email filtering solutions that can detect and block suspicious file attachments. Network monitoring should be enhanced to detect potential exploitation attempts through anomalous file access patterns or unusual network behavior associated with compromised systems. Regular security awareness training for users can help reduce the risk of successful social engineering attacks that rely on user interaction to deliver malicious payloads.