CVE-2018-25032 in Siebel CRM
Summary
by MITRE • 03/25/2022
zlib before 1.2.12 allows memory corruption when deflating (i.e., when compressing) if the input has many distant matches.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 07/15/2026
The vulnerability identified as CVE-2018-25032 represents a critical memory corruption issue within the zlib compression library affecting versions prior to 1.2.12. This flaw specifically manifests during the deflation process, which is the compression operation performed by zlib when processing data. The vulnerability stems from insufficient input validation and memory management when handling compressed data with numerous distant matches, creating a scenario where the compression algorithm can overwrite memory boundaries. The issue falls under the category of memory safety vulnerabilities and is classified as a buffer overflow condition that can lead to arbitrary code execution or system instability. This vulnerability directly impacts software applications that rely on zlib for compression operations, particularly those handling large datasets or data streams with repetitive patterns.
The technical root cause of CVE-2018-25032 lies in the deflate compression algorithm implementation within zlib where the compression routine fails to properly validate the distance values in the input data stream. When the compression algorithm encounters input data containing many distant matches, the internal state management becomes corrupted due to improper handling of the distance and length fields used in the LZ77 compression algorithm. This specific scenario occurs when the deflate routine attempts to reference memory locations that exceed the allocated buffer boundaries, leading to memory corruption. The vulnerability is particularly dangerous because it can be triggered through normal compression operations without requiring special privileges or complex exploitation techniques, making it highly accessible to attackers. The flaw demonstrates characteristics consistent with CWE-121, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1059.007 for execution through decompression or compression operations.
The operational impact of this vulnerability extends across numerous software systems and applications that depend on zlib for compression functionality. Any application that performs compression operations using zlib versions before 1.2.12 could be susceptible to memory corruption attacks, potentially leading to application crashes, denial of service conditions, or more severe exploitation scenarios. The vulnerability affects not only standalone applications but also network services, web servers, and database systems that utilize zlib compression for data transmission or storage. Attackers could exploit this weakness to cause system instability or potentially execute arbitrary code on affected systems, particularly in environments where compressed data is processed from untrusted sources. The widespread adoption of zlib across various platforms and applications means that the potential attack surface for this vulnerability is extensive, affecting both enterprise and consumer software ecosystems.
Mitigation strategies for CVE-2018-25032 primarily focus on upgrading to zlib version 1.2.12 or later, which includes patches specifically addressing the memory corruption issue. System administrators should prioritize updating zlib libraries across all affected systems, particularly in server environments where compressed data processing occurs. Additional protective measures include implementing input validation for compressed data streams, monitoring for unusual compression patterns, and configuring application-level restrictions on compression operations. Organizations should also consider deploying intrusion detection systems that can identify potential exploitation attempts targeting this vulnerability. The fix implemented in zlib 1.2.12 involves strengthening the distance and length validation logic within the deflate routine, ensuring proper boundary checking during memory allocation and access operations. Security teams should conduct thorough vulnerability assessments to identify all systems using affected zlib versions and implement comprehensive patch management procedures to prevent exploitation attempts.