CVE-2021-41973 | Apache MINA HTTP listener DOS

In Apache MINA, a specifically crafted, malformed HTTP request may cause the HTTP Header decoder to loop indefinitely. The decoder assumed that the HTTP Header begins at the beginning of the buffer and loops if there is more data than expected. Please update MINA to 2.1.5 or greater.

Published: 2021-11-01 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-41973 is rated Moderate Risk (56.8/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.15%). EPSS rose +1.22% over the last day, indicating growing attacker interest. 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-2021-41973

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 2026-06-08 0.93% 2.15% +1.22%
2 2026-05-27 1.81% 0.93% -0.88%
3 2026-05-02 — 1.81% —

Full EPSS history (35 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-41973

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:N/UI:R/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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]
4.3 2.0 MEDIUM
AV:N/AC:M/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:M)
Exploitation needs some favorable conditions, but not exceptional ones.
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.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-41973

GitHub Security Advisory for CVE-2021-41973

OS Trackers for CVE-2021-41973

vendor priority summary link
debian unimportant CVE-2021-41973 unimportant priority: Debian including 2 source packages (mina, mina2), 7 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6, open 1. https://security-tracker.debian.org/tracker/CVE-2021-41973
redhat medium — https://access.redhat.com/security/cve/CVE-2021-41973
ubuntu medium CVE-2021-41973 medium priority: Ubuntu including 2 source packages (mina, mina2), 18 status rows across 9 suites (bionic, focal, jammy, noble, oracular, plucky, questing, upstream, xenial): needs-triage 8, not-affected 6, ignored 2, DNE 1, released 1. https://ubuntu.com/security/CVE-2021-41973

Affected software / configurations for CVE-2021-41973

Vendor Product Version Raw CPE
apache mina < 2.0.22 cpe:2.3:a:apache:mina:*:*:*:*:*:*:*:*
apache mina >= 2.1.0, < 2.1.5 cpe:2.3:a:apache:mina:*:*:*:*:*:*:*:*
oracle banking_payments 14.5 cpe:2.3:a:oracle:banking_payments:14.5:*:*:*:*:*:*:*
oracle banking_trade_finance_process_management 14.5 cpe:2.3:a:oracle:banking_trade_finance_process_management: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 customer_management_and_segmentation_foundation 18.0 cpe:2.3:a:oracle:customer_management_and_segmentation_foundation:18.0:*:*:*:*:*:*:*
oracle customer_management_and_segmentation_foundation 19.0 cpe:2.3:a:oracle:customer_management_and_segmentation_foundation:19.0:*:*:*:*:*:*:*
oracle flexcube_universal_banking >= 14.0, <= 14.3 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 fusion_middleware_common_libraries_and_tools 12.2.1.3.0 cpe:2.3:a:oracle:fusion_middleware_common_libraries_and_tools:12.2.1.3.0:*:*:*:*:*:*:*
oracle fusion_middleware_common_libraries_and_tools 12.2.1.4.0 cpe:2.3:a:oracle:fusion_middleware_common_libraries_and_tools:12.2.1.4.0:*:*:*:*:*:*:*
oracle fusion_middleware_common_libraries_and_tools 14.1.1.0.0 cpe:2.3:a:oracle:fusion_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:*:*:*:*:*:*:*

References for CVE-2021-41973

cvelogic Threat Intelligence