CVE-2020-11995 | Apache Dubbo default deserialization protocol Hessian2 cause CRE

A deserialization vulnerability existed in dubbo 2.7.5 and its earlier versions, which could lead to malicious code execution. Most Dubbo users use Hessian2 as the default serialization/deserialization protool, during Hessian2 deserializing the HashMap object, some functions in the classes stored in HasMap will be executed after a series of program calls, however, those special functions may cause remote command execution. For example, the hashCode() function of the EqualsBean class in rome-1.7.0.jar will cause the remotely load malicious classes and execute malicious code by constructing a malicious request. This issue was fixed in Apache Dubbo 2.6.9 and 2.7.8.

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

CVE-2020-11995 is rated High Risk (74.9/100): CVSS Critical severity, with high exploitation likelihood (EPSS 5.84%, 92th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +3.42% over the last day, indicating growing attacker interest. 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-2020-11995

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 2.42% 5.84% +3.42%
2 2026-05-13 1.74% 2.42% +0.68%
3 2026-04-21 — 1.74% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-11995

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]
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-2020-11995

GitHub Security Advisory for CVE-2020-11995

GHSA-74mg-6xqx-2vrq · Severity: critical · Ecosystem: maven — Deserialization exploitation in Apache Dubbo

Affected software / configurations for CVE-2020-11995

Vendor Product Version Raw CPE
apache dubbo >= 2.5.0, <= 2.5.10 cpe:2.3:a:apache:dubbo:*:*:*:*:*:*:*:*
apache dubbo >= 2.6.0, <= 2.6.8 cpe:2.3:a:apache:dubbo:*:*:*:*:*:*:*:*
apache dubbo >= 2.7.0, <= 2.7.7 cpe:2.3:a:apache:dubbo:*:*:*:*:*:*:*:*

References for CVE-2020-11995

cvelogic Threat Intelligence