CVE-2023-6992: zlib Input Validation Flaw — Fix

Description

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.

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CVSS v3.1 Score

4.0

MEDIUM

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

Weakness Type (CWE)

CWE-20 Improper Input Validation

CWE-122 CWE-122

CWE-126 CWE-126

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
cloudflare	zlib	< 2023-11-16

References

Advisories & Patches

https://github.com/cloudflare/zlib/security/advisories/GHSA-vww9-j87r-4cqh https://github.com/cloudflare/zlib/security/advisories/GHSA-vww9-j87r-4cqh

Other References

https://github.com/cloudflare/zlib https://github.com/cloudflare/zlib

Frequently Asked Questions

What is CVE-2023-6992? +

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. It has a CVSS v3.1 base score of 4.0 (MEDIUM).

How severe is CVE-2023-6992? +

CVE-2023-6992 has a CVSS v3.1 score of 4.0 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2023-6992? +

CVE-2023-6992 affects products from cloudflare, specifically: zlib. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-6992? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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