CVE-2020-29577

The official znc docker images before 1.7.1-slim contain a blank password for a root user. Systems using the znc docker container deployed by affected versions of the Docker image may allow an remote attacker to achieve root access with a blank password.

Published: 2020-12-08 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-29577 is rated High Risk (67.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.29%). High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-29577

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 2.07% 2.29% +0.22%
2 2025-03-30 4.06% 2.07% -1.98%
3 2025-03-29 — 4.06% —

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-29577

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 10.0 [email protected]

Weakness enumeration for CVE-2020-29577

Affected software / configurations for CVE-2020-29577

Vendor Product Version Raw CPE
znc znc_docker_image 1.6 cpe:2.3:a:znc:znc_docker_image:1.6:*:*:*:*:*:*:*
znc znc_docker_image 1.6-slim cpe:2.3:a:znc:znc_docker_image:1.6-slim:*:*:*:*:*:*:*
znc znc_docker_image 1.6.4 cpe:2.3:a:znc:znc_docker_image:1.6.4:*:*:*:*:*:*:*
znc znc_docker_image 1.6.4-slim cpe:2.3:a:znc:znc_docker_image:1.6.4-slim:*:*:*:*:*:*:*
znc znc_docker_image 1.6.5 cpe:2.3:a:znc:znc_docker_image:1.6.5:*:*:*:*:*:*:*
znc znc_docker_image 1.6.5-slim cpe:2.3:a:znc:znc_docker_image:1.6.5-slim:*:*:*:*:*:*:*
znc znc_docker_image 1.6.6 cpe:2.3:a:znc:znc_docker_image:1.6.6:*:*:*:*:*:*:*
znc znc_docker_image 1.6.6-slim cpe:2.3:a:znc:znc_docker_image:1.6.6-slim:*:*:*:*:*:*:*
znc znc_docker_image 1.7.0 cpe:2.3:a:znc:znc_docker_image:1.7.0:*:*:*:*:*:*:*
znc znc_docker_image 1.7.0-slim cpe:2.3:a:znc:znc_docker_image:1.7.0-slim:*:*:*:*:*:*:*
znc znc_docker_image 1.7.1-slim cpe:2.3:a:znc:znc_docker_image:1.7.1-slim:*:*:*:*:*:*:*

References for CVE-2020-29577

cvelogic Threat Intelligence