CVE-2025-21043: Samsung Android RCE Vulnerability

CVE-2025-21043 Overview

CVE-2025-21043 is a critical out-of-bounds write vulnerability in Samsung's libimagecodec.quram.so library, a core component responsible for image processing on Samsung Android devices. This vulnerability allows remote attackers to execute arbitrary code on affected devices without requiring any user interaction or privileges. The flaw resides in Samsung's proprietary image codec implementation developed by Quram, which handles image decoding operations across the Android operating system.

Critical Impact

This vulnerability is actively exploited in the wild and has been added to the CISA Known Exploited Vulnerabilities (KEV) catalog. Remote attackers can achieve arbitrary code execution on Samsung Android devices, potentially leading to complete device compromise.

Affected Products

• Samsung Android 13.0 (all SMR releases prior to SMR Sep-2025 Release 1)
• Samsung Android 14.0 (all SMR releases prior to SMR Sep-2025 Release 1)
• Samsung Android 15.0 (all SMR releases prior to SMR Sep-2025 Release 1)
• Samsung Android 16.0 (all SMR releases prior to SMR Sep-2025 Release 1)

Discovery Timeline

• September 12, 2025 - CVE-2025-21043 published to NVD
• October 30, 2025 - Last updated in NVD database

Technical Details for CVE-2025-21043

Vulnerability Analysis

The vulnerability exists within Samsung's libimagecodec.quram.so shared library, which is responsible for encoding and decoding various image formats on Samsung Android devices. An out-of-bounds write condition (CWE-787) occurs when the library processes specially crafted image files. This type of memory corruption vulnerability can allow attackers to overwrite adjacent memory locations beyond the allocated buffer boundaries.

The exploitation potential of this vulnerability is significant given that the library is invoked automatically when processing images from various sources, including messaging applications, email clients, web browsers, and file managers. An attacker can deliver a malicious image file through any of these channels, and the vulnerable library will process it without user intervention.

Root Cause

The root cause of CVE-2025-21043 is improper bounds checking within the image decoding routines of libimagecodec.quram.so. When parsing image data, the library fails to properly validate input parameters or calculated offsets before writing decoded pixel data to memory buffers. This allows an attacker to supply malformed image dimensions, compressed data, or metadata that causes write operations to occur outside the intended memory region.

Attack Vector

This vulnerability can be exploited remotely over the network without requiring any user privileges or interaction. The attack vector involves delivering a maliciously crafted image file to a target Samsung Android device through various channels:

The attack flow typically follows this pattern: An attacker crafts a malicious image file designed to trigger the out-of-bounds write condition when processed by libimagecodec.quram.so. This file can be delivered via MMS messages, email attachments, social media platforms, malicious websites, or any application that processes images. When the image is automatically processed (for thumbnail generation, preview display, or gallery indexing), the vulnerability is triggered, allowing the attacker to corrupt memory and potentially achieve arbitrary code execution.

Due to the nature of image processing on Android devices, exploitation may occur automatically without any direct user action, as the system often processes images in the background for thumbnail generation and media indexing.

Detection Methods for CVE-2025-21043

Indicators of Compromise

• Unexpected crashes or instability in the Samsung Gallery, Messages, or other media-processing applications
• Unusual memory allocation patterns or heap corruption indicators in system logs related to libimagecodec.quram.so
• Suspicious image files with malformed headers or unusual dimensions in device storage or temporary directories
• Evidence of unauthorized code execution or process spawning following image processing events

Detection Strategies

• Monitor Mobile Device Management (MDM) solutions for firmware versions predating SMR Sep-2025 Release 1
• Implement network-level scanning for known malicious image patterns targeting Samsung devices
• Deploy endpoint detection solutions capable of monitoring native library behavior on Android devices
• Review application crash reports for patterns indicating memory corruption in image processing libraries

Monitoring Recommendations

• Enable enhanced logging for media processing activities on managed Samsung devices
• Implement file integrity monitoring for image files received through communication channels
• Monitor for unusual process behavior or privilege escalation following image processing events
• Track Samsung Security Update compliance across enterprise device fleets using MDM tools

How to Mitigate CVE-2025-21043

Immediate Actions Required

• Apply the Samsung SMR Sep-2025 Release 1 security update immediately on all affected Samsung Android devices
• Prioritize patching for devices used in sensitive environments or with access to corporate resources
• Consider restricting automatic media processing features on critical devices until patching is complete
• Verify patch deployment using the Samsung Mobile Security Advisory as reference

Patch Information

Samsung has addressed this vulnerability in the SMR Sep-2025 Release 1 security maintenance release. The patch is available through Samsung's standard firmware update channels. Organizations should verify the security patch level on Samsung devices shows September 2025 or later. The security update includes fixes for the bounds checking issues in libimagecodec.quram.so that enable this remote code execution vulnerability.

For detailed patch information and affected device models, refer to the Samsung Mobile Security Update bulletin. This vulnerability is also tracked in the CISA Known Exploited Vulnerabilities Catalog, which mandates federal agencies to apply mitigations by the specified deadline.

Workarounds

• Restrict download and processing of images from untrusted sources on unpatched devices
• Disable automatic media download in messaging applications (MMS, email, chat apps) where possible
• Implement network-level filtering to block suspicious image files from reaching endpoint devices
• Consider temporarily isolating unpatched Samsung devices from corporate networks containing sensitive data

# Verify Samsung security patch level on device
# Settings > About Phone > Software Information > Android Security Patch Level
# Ensure date shows September 2025 or later

# For enterprise MDM environments, query device security patch levels
# Example using Android Enterprise API or MDM console
# Filter devices where security_patch_level < "2025-09-01"