CVE-2026-20244
Description
A flaw was found in ClamAV's DMG file format parser. An unauthenticated, remote attacker can exploit this vulnerability by submitting a specially crafted DMG file for scanning. Improper boundary checks during the scanning process can lead to an integer overflow, primarily affecting 32-bit platforms. A successful exploit could cause the ClamAV scanning process to terminate, resulting in a Denial of Service (DoS) condition.
Statement
This Important denial-of-service flaw in ClamAV's DMG file parser primarily impacts 32-bit Red Hat environments. Remote, unauthenticated attackers can trigger a service disruption by submitting a crafted DMG file for scanning, leading to the ClamAV process terminating. This is critical for systems relying on ClamAV for continuous threat detection.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Memory); DoS: Instability
This weakness can generally lead to undefined behavior and therefore crashes. When the calculated result is used for resource allocation, this weakness can cause too many (or too few) resources to be allocated, possibly enabling crashes if the product requests more resources than can be provided.
Integrity
Technical Impact: Modify Memory
If the value in question is important to data (as opposed to flow), simple data corruption has occurred. Also, if the overflow/wraparound results in other conditions such as buffer overflows, further memory corruption may occur.
Confidentiality,Availability,Access Control
Technical Impact: Execute Unauthorized Code or Commands; Bypass Protection Mechanism
This weakness can sometimes trigger buffer overflows, which can be used to execute arbitrary code. This is usually outside the scope of the product's implicit security policy.
Availability,Other
Technical Impact: Alter Execution Logic; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
If the overflow/wraparound occurs in a loop index variable, this could cause the loop to terminate at the wrong time - too early, too late, or not at all (i.e., infinite loops). With too many iterations, some loops could consume too many resources such as memory, file handles, etc., possibly leading to a crash or other DoS.
Access Control
Technical Impact: Bypass Protection Mechanism
If integer values are used in security-critical decisions, such as calculating quotas or allocation limits, integer overflows can be used to cause an incorrect security decision.
Frequently Asked Questions
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