{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/sail/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-40493"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["SAIL"],"_cs_severities":["critical"],"_cs_tags":["cve-2026-40493","heap-overflow","image-processing","sail"],"_cs_type":"advisory","_cs_vendors":["SAIL"],"content_html":"\u003cp\u003eSAIL (Simple API for Images Loading) is a cross-platform library used for loading and saving images, supporting features like animation, metadata handling, and ICC profiles. A critical vulnerability, CVE-2026-40493, has been identified within the PSD codec of SAIL. This flaw stems from an inconsistency in how the library calculates bytes per pixel (bpp) compared to the actual memory allocated for pixel data. Specifically, when processing images in LAB mode with \u003ccode\u003echannels=3\u003c/code\u003e and \u003ccode\u003edepth=16\u003c/code\u003e, the computed \u003ccode\u003ebpp\u003c/code\u003e value doesn't align with the memory allocated by the \u003ccode\u003eBPP40_CIE_LAB\u003c/code\u003e format, resulting in a heap buffer overflow during pixel write operations. The vulnerability affects versions prior to commit c930284445ea3ff94451ccd7a57c999eca3bc979, which contains the necessary patch to resolve this issue. Successful exploitation could lead to arbitrary code execution.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker crafts a malicious PSD image specifically designed to trigger the vulnerability. This image is created with LAB color mode, 3 channels, and a depth of 16 bits per channel.\u003c/li\u003e\n\u003cli\u003eThe victim application utilizes the SAIL library to load the crafted PSD image. This could be a photo editor, image viewer, or any other software incorporating SAIL for image processing.\u003c/li\u003e\n\u003cli\u003eThe PSD codec within SAIL calculates the \u003ccode\u003ebpp\u003c/code\u003e value based on the \u003ccode\u003echannels\u003c/code\u003e and \u003ccode\u003edepth\u003c/code\u003e header fields. In this specific case, the calculation results in a \u003ccode\u003ebpp\u003c/code\u003e value of 6.\u003c/li\u003e\n\u003cli\u003eThe pixel buffer is allocated based on the resolved pixel format, \u003ccode\u003eBPP40_CIE_LAB\u003c/code\u003e, which allocates only 5 bytes per pixel.\u003c/li\u003e\n\u003cli\u003eDuring pixel writing, the code attempts to write 6 bytes of data into a buffer allocated for only 5 bytes, resulting in a one-byte heap buffer overflow. This overflow occurs deterministically on every row of the image.\u003c/li\u003e\n\u003cli\u003eThe heap buffer overflow corrupts adjacent memory regions on the heap.\u003c/li\u003e\n\u003cli\u003eDepending on the overwritten data, the attacker could potentially gain control of program execution by overwriting function pointers or other critical data structures.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves arbitrary code execution on the victim's machine, leading to system compromise.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-40493 allows an attacker to achieve arbitrary code execution on a vulnerable system. This could lead to complete system compromise, data exfiltration, or denial-of-service. Applications that rely on the SAIL library to process PSD images are at risk. The vulnerability's high CVSS score (9.8) indicates its critical severity and potential for widespread impact. The number of affected systems depends on the adoption rate of the SAIL library in various software applications across different sectors.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade to a version of SAIL that includes commit c930284445ea3ff94451ccd7a57c999eca3bc979 or later to patch CVE-2026-40493.\u003c/li\u003e\n\u003cli\u003eMonitor applications that use the SAIL library for unexpected crashes or anomalous behavior, which could indicate exploitation attempts. Enable process creation logging (Sysmon on Windows) to activate the rule detecting abnormal processes spawned by image processing applications.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect SAIL PSD Heap Overflow\u003c/code\u003e to identify potential exploitation attempts based on process creation events.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T12:00:00Z","date_published":"2024-01-03T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-03-sail-heap-overflow/","summary":"A heap buffer overflow vulnerability exists in the SAIL image loading library's PSD codec due to a mismatch in bytes-per-pixel calculation and pixel buffer allocation in LAB mode, leading to potential code execution.","title":"SAIL Library PSD Codec Heap Buffer Overflow Vulnerability (CVE-2026-40493)","url":"https://feed.craftedsignal.io/briefs/2024-01-03-sail-heap-overflow/"}],"language":"en","title":"CraftedSignal Threat Feed - SAIL","version":"https://jsonfeed.org/version/1.1"}