CVE-2021-30129 | DoS/OOM leak vulnerability in Apache Mina SSHD Server

A vulnerability in sshd-core of Apache Mina SSHD allows an attacker to overflow the server causing an OutOfMemory error. This issue affects the SFTP and port forwarding features of Apache Mina SSHD version 2.0.0 and later versions. It was addressed in Apache Mina SSHD 2.7.0

Published: 2021-07-12 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-30129 is rated Low Risk (38.9/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.23%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2021-30129

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 2025-11-21 3.22% 0.23% -3.00%
2 2025-11-18 0.24% 3.22% +2.99%
3 2025-06-10 — 0.24% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-30129

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/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:L)
A normal user session is enough; they don’t have to be admin.
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.
 2.8 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/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:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-30129

GitHub Security Advisory for CVE-2021-30129

GHSA-9279-7hph-r3xw · Severity: high · Ecosystem: maven — Buffer Overflow in Apache Mina SSHD

OS Trackers for CVE-2021-30129

vendor priority summary link
debian unimportant CVE-2021-30129 unimportant priority: Debian including 1 source packages (libmina-sshd-java), 3 status rows across 3 suites (forky, sid, trixie): resolved 3. https://security-tracker.debian.org/tracker/CVE-2021-30129
redhat medium — https://access.redhat.com/security/cve/CVE-2021-30129

Affected software / configurations for CVE-2021-30129

Vendor Product Version Raw CPE
apache sshd >= 2.0.0, < 2.7.0 cpe:2.3:a:apache:sshd:*:*:*:*:*:*:*:*
oracle banking_payments 14.5 cpe:2.3:a:oracle:banking_payments:14.5:*:*:*:*:*:*:*
oracle banking_trade_finance 14.5 cpe:2.3:a:oracle:banking_trade_finance:14.5:*:*:*:*:*:*:*
oracle banking_treasury_management 14.5 cpe:2.3:a:oracle:banking_treasury_management:14.5:*:*:*:*:*:*:*
oracle communications_cloud_native_core_console 1.9.0 cpe:2.3:a:oracle:communications_cloud_native_core_console:1.9.0:*:*:*:*:*:*:*
oracle flexcube_universal_banking >= 14.0.0, <= 14.3.0 cpe:2.3:a:oracle:flexcube_universal_banking:*:*:*:*:*:*:*:*
oracle flexcube_universal_banking 14.5 cpe:2.3:a:oracle:flexcube_universal_banking:14.5:*:*:*:*:*:*:*
oracle middleware_common_libraries_and_tools 12.2.1.3.0 cpe:2.3:a:oracle:middleware_common_libraries_and_tools:12.2.1.3.0:*:*:*:*:*:*:*
oracle middleware_common_libraries_and_tools 12.2.1.4.0 cpe:2.3:a:oracle:middleware_common_libraries_and_tools:12.2.1.4.0:*:*:*:*:*:*:*
oracle middleware_common_libraries_and_tools 14.1.1.0.0 cpe:2.3:a:oracle:middleware_common_libraries_and_tools:14.1.1.0.0:*:*:*:*:*:*:*
oracle oss_support_tools 2.12.42 cpe:2.3:a:oracle:oss_support_tools:2.12.42:*:*:*:*:*:*:*
oracle retail_customer_management_and_segmentation_foundation 18.0 cpe:2.3:a:oracle:retail_customer_management_and_segmentation_foundation:18.0:*:*:*:*:*:*:*
oracle retail_customer_management_and_segmentation_foundation 19.0 cpe:2.3:a:oracle:retail_customer_management_and_segmentation_foundation:19.0:*:*:*:*:*:*:*

References for CVE-2021-30129

cvelogic Threat Intelligence