Cloudflare zlib Deflate Heap Buffer Overflow
CVE-2023-6992 Published on January 4, 2024
Memory corruption issues is Cloudflare zlib implementation
Cloudflare version of zlib library was found to be vulnerable to memory corruption issues affecting the deflation algorithm implementation (deflate.c). The issues resulted from improper input validation and heap-based buffer overflow.
A local attacker could exploit the problem during compression using a crafted malicious file potentially leading to denial of service of the software.
Patches: The issue has been patched in commit 8352d10 https://github.com/cloudflare/zlib/commit/8352d108c05db1bdc5ac3bdf834dad641694c13c . The upstream repository is not affected.
Vulnerability Analysis
CVE-2023-6992 is exploitable with local system access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, with no impact on integrity and availability.
Weakness Types
Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
Heap-based Buffer Overflow
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
Buffer Over-read
The software reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer. This typically occurs when the pointer or its index is incremented to a position beyond the bounds of the buffer or when pointer arithmetic results in a position outside of the valid memory location to name a few. This may result in exposure of sensitive information or possibly a crash.
Products Associated with CVE-2023-6992
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Affected Versions
Cloudflare zlib:- Before 8352d10 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.