How severe is CVE-2023-6992?

CVE-2023-6992 has a CVSS 3.x base score of 4.0, rated medium severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.

Is CVE-2023-6992 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-6992?

CVE-2023-6992 affects Cloudflare Zlib. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-6992?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2023-6992 have an EU (EUVD) identifier?

Yes. CVE-2023-6992 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-59184.

When was CVE-2023-6992 published?

CVE-2023-6992 was published on 2024-01-04 and last updated on 2026-06-17.

CVE-2023-6992

CVE-2023-6992 is a medium-severity vulnerability in Cloudflare Zlib with a CVSS 3.x base score of 4.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Medium (CVSS 3.x base score 4.0)
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2023-59184
Weakness: CWE-787
Affected product: Cloudflare Zlib
Published: 2024-01-04
Last modified: 2026-06-17

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.

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.
How severe is CVE-2023-6992?: CVE-2023-6992 has a CVSS 3.x base score of 4.0, rated medium severity. It is exploitable over local access with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2023-6992 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-6992?: CVE-2023-6992 affects Cloudflare Zlib. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-6992?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2023-6992 have an EU (EUVD) identifier?: Yes. CVE-2023-6992 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-59184.
When was CVE-2023-6992 published?: CVE-2023-6992 was published on 2024-01-04 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:cloudflare:zlib:*:*:*:*:*:*:*:*

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