How severe is CVE-2020-4355?

CVE-2020-4355 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2020-4355 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-4355?

CVE-2020-4355 primarily affects Ibm Db2. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-4355?

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

When was CVE-2020-4355 published?

CVE-2020-4355 was published on 2020-07-01 and last updated on 2026-06-17.

CVE-2020-4355

CVE-2020-4355 is a medium-severity vulnerability in Ibm Db2 with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Ibm Db2
Published: 2020-07-01
Last modified: 2026-06-17

Description

IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, 11.1, and 11.5 is vulnerable to a denial of service, caused by improper handling of Secure Sockets Layer (SSL) renegotiation requests. By sending specially-crafted requests, a remote attacker could exploit this vulnerability to increase the resource usage on the system. IBM X-Force ID: 178507.

Frequently asked questions

What is CVE-2020-4355?: IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) 9.7, 10.1, 10.5, 11.1, and 11.5 is vulnerable to a denial of service, caused by improper handling of Secure Sockets Layer (SSL) renegotiation requests. By sending specially-crafted requests, a remote attacker could exploit this vulnerability to increase the resource usage on the system. IBM X-Force ID: 178507.
How severe is CVE-2020-4355?: CVE-2020-4355 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2020-4355 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-4355?: CVE-2020-4355 primarily affects Ibm Db2. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-4355?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-4355 published?: CVE-2020-4355 was published on 2020-07-01 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:ibm:db2:9.7.0.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:db2:10.1.0.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:db2:10.5.0.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:db2:11.1.0.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:db2:11.5.0.0:*:*:*:*:*:*:*

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