CVE-2021-21048 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 a Memory Corruption 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 versions 21.2.4 and earlier as well as 22.1.1 and earlier contain a memory corruption vulnerability that arises during the parsing of specially crafted files. This vulnerability falls under the category of memory safety issues and represents a critical security flaw that could be exploited by unauthenticated attackers. The flaw occurs within the application's file parsing mechanism, specifically when processing malformed input data that triggers improper memory handling behaviors. The vulnerability is classified as a memory corruption issue that can lead to arbitrary code execution when successfully exploited. The attack requires user interaction since victims must open the malicious file for the exploit to be triggered, making it a user-initiated privilege escalation vector rather than a fully automated attack.
The technical implementation of this vulnerability stems from insufficient input validation and memory management within Photoshop's file parsing routines. When the application encounters a crafted file structure, it fails to properly validate the data boundaries and memory allocation patterns, leading to memory corruption that can be leveraged to execute arbitrary code. This type of vulnerability aligns with common weakness enumerations such as CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations. The vulnerability is particularly dangerous because it operates within the context of the currently logged-in user, meaning that successful exploitation would allow an attacker to execute malicious code with the same privileges as the user running Photoshop. This creates a significant risk for both personal and enterprise environments where Photoshop is commonly used for image processing and creative work.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential system compromise and data breach scenarios. Attackers could craft malicious files designed to exploit this weakness, potentially gaining unauthorized access to sensitive information or establishing persistent access to compromised systems. The requirement for user interaction means that social engineering campaigns could be employed to deliver these malicious files through email attachments, download links, or other common attack vectors. This vulnerability particularly affects creative professionals, graphic designers, and content creators who frequently handle external image files, making it a prime target for targeted attacks. The exploitation chain typically involves crafting a malicious file that, when opened by a victim using an affected Photoshop version, triggers the memory corruption and subsequently executes attacker-controlled code. This behavior aligns with attack patterns documented in the mitre att&ck framework under techniques such as initial access through malicious files and privilege escalation through code execution.
Organizations and individuals using affected versions of Adobe Photoshop should immediately implement mitigations to protect against potential exploitation attempts. The most effective immediate solution involves updating to the latest available version of Adobe Photoshop that contains patches for this vulnerability, as Adobe has released security updates addressing this specific flaw. System administrators should also implement file validation measures and user education programs to reduce the risk of opening malicious files. Additional protective measures include restricting user privileges when running Photoshop, implementing application whitelisting policies, and monitoring for suspicious file access patterns. The vulnerability demonstrates the importance of keeping creative software updated, as these applications often handle untrusted data from external sources and can become attack vectors when outdated. Security teams should also consider implementing network-based intrusion detection systems that can identify and block attempts to deliver malicious files through email or web-based channels. Regular vulnerability assessments should include checking for outdated software versions that may contain similar memory corruption vulnerabilities in other Adobe applications or third-party software used in creative workflows.