CVE-2020-15127 | Denial of service in Contour

In Contour ( Ingress controller for Kubernetes) before version 1.7.0, a bad actor can shut down all instances of Envoy, essentially killing the entire ingress data plane. GET requests to /shutdown on port 8090 of the Envoy pod initiate Envoy's shutdown procedure. The shutdown procedure includes flipping the readiness endpoint to false, which removes Envoy from the routing pool. When running Envoy (For example on the host network, pod spec hostNetwork=true), the shutdown manager's endpoint is accessible to anyone on the network that can reach the Kubernetes node that's running Envoy. There is no authentication in place that prevents a rogue actor on the network from shutting down Envoy via the shutdown manager endpoint. Successful exploitation of this issue will lead to bad actors shutting down all instances of Envoy, essentially killing the entire ingress data plane. This is fixed in version 1.7.0.

Published: 2020-08-05 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-15127 is rated Moderate Risk (47.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.31%). Mandatory action: Review affected assets and schedule 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-2020-15127

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 2025-03-30 0.37% 0.31% -0.06%
2 2025-03-29 0.31% 0.37% +0.06%
3 2025-03-17 0.31%

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-15127

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P 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:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-15127

OS Trackers for CVE-2020-15127

vendor priority summary link
alpine high CVE-2020-15127: 1 source package rows (contour); 5 state rows across 3 repos (3.22-community, 3.23-community, edge-community); fixed 0, open 5. https://security.alpinelinux.org/vuln/CVE-2020-15127

Affected software / configurations for CVE-2020-15127

Vendor Product Version Raw CPE
projectcontour contour < 1.7.0 cpe:2.3:a:projectcontour:contour:*:*:*:*:*:kubernetes:*:*

References for CVE-2020-15127

cvelogic Threat Intelligence