How severe is CVE-2019-5163?

CVE-2019-5163 has a CVSS 3.x base score of 7.5, rated high 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 high.

Is CVE-2019-5163 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-5163?

CVE-2019-5163 primarily affects Shadowsocks Shadowsocks-libev. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-5163?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-5163 published?

CVE-2019-5163 was published on 2019-12-03 and last updated on 2026-06-17.

CVE-2019-5163

CVE-2019-5163 is a high-severity vulnerability in Shadowsocks Shadowsocks-libev with a CVSS 3.x base score of 7.5. 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-306.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 4.3
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-306
Affected product: Shadowsocks Shadowsocks-libev
Published: 2019-12-03
Last modified: 2026-06-17

Description

An exploitable denial-of-service vulnerability exists in the UDPRelay functionality of Shadowsocks-libev 3.3.2. When utilizing a Stream Cipher and a local_address, arbitrary UDP packets can cause a FATAL error code path and exit. An attacker can send arbitrary UDP packets to trigger this vulnerability.

Frequently asked questions

What is CVE-2019-5163?: An exploitable denial-of-service vulnerability exists in the UDPRelay functionality of Shadowsocks-libev 3.3.2. When utilizing a Stream Cipher and a local_address, arbitrary UDP packets can cause a FATAL error code path and exit. An attacker can send arbitrary UDP packets to trigger this vulnerability.
How severe is CVE-2019-5163?: CVE-2019-5163 has a CVSS 3.x base score of 7.5, rated high 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 high.
Is CVE-2019-5163 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-5163?: CVE-2019-5163 primarily affects Shadowsocks Shadowsocks-libev. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-5163?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-5163 published?: CVE-2019-5163 was published on 2019-12-03 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:shadowsocks:shadowsocks-libev:3.3.2:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:backports:sle-15:sp1:*:*:*:*:*:*
cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*

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