CVE-2021-38443 | Eclipse CycloneDDS Improper Handling of Syntactically Invalid Structure

Eclipse CycloneDDS versions prior to 0.8.0 improperly handle invalid structures, which may allow an attacker to write arbitrary values in the XML parser.

Published: 2022-05-05 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-38443 is rated Moderate Risk (56/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.08%). EPSS rose +1.93% 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-2021-38443

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 0.15% 2.08% +1.93%
2 2025-05-14 0.13% 0.15% +0.02%
3 2025-05-13 — 0.13% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-38443

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.6 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 4.7 [email protected]
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]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/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:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2021-38443

OS Trackers for CVE-2021-38443

vendor priority summary link
debian not yet assigned CVE-2021-38443 not yet assigned priority: Debian including 1 source packages (cyclonedds), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-38443
ubuntu medium CVE-2021-38443 medium priority: Ubuntu including 1 source packages (cyclonedds), 10 status rows across 10 suites (impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, upstream): ignored 6, needs-triage 4. https://ubuntu.com/security/CVE-2021-38443

Affected software / configurations for CVE-2021-38443

Vendor Product Version Raw CPE
eclipse cyclonedds < 0.8.0 cpe:2.3:a:eclipse:cyclonedds:*:*:*:*:*:*:*:*

References for CVE-2021-38443

cvelogic Threat Intelligence