Is CVE-2009-4355 in the CISA KEV catalog?

No. CVE-2009-4355 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2009-4355?

CVE-2009-4355 has a CVSS v2 base score of 5.0 (MEDIUM).

What is the EPSS score for CVE-2009-4355?

CVE-2009-4355 has an EPSS score of 8.94% (95th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2009-4355?

Upgrade openssl on debian 11 to 0.9.8k-8 or later.

CVE & CISA-KEV Catalog

CVE-2009-4355

MEDIUMEPSS 95th pctl

5.0

CVSS v2

NVD

Description

Memory leak in the zlib_stateful_finish function in crypto/comp/c_zlib.c in OpenSSL 0.9.8l and earlier and 1.0.0 Beta through Beta 4 allows remote attackers to cause a denial of service (memory consumption) via vectors that trigger incorrect calls to the CRYPTO_cleanup_all_ex_data function, as demonstrated by use of SSLv3 and PHP with the Apache HTTP Server, a related issue to CVE-2008-1678.

CWE-399Resource Management Errors

How to fix

Remediation Available

opensslDebian

Fixed in:0.9.8k-8CVE-2009-4355

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v2 Vector

No CVSS vector data available.

Exploit Intelligence

8.94%probability of exploitation in 30 days

95thpercentile

High risk: more likely to be exploited than 95% of all known CVEs.

References

Related Vulnerabilities

Other CWE-399 (Resource Management Errors) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2009-3103	High	10.0	90%	-	-
CVE-2009-0075	High	9.3	85%	-	-
CVE-2005-1790	Low	2.6	83%	-	-
CVE-2010-0806	High	8.8	82%	KEV	-
CVE-2009-2526	High	7.8	82%	-	-
CVE-2015-1868	High	7.8	82%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-23.