CVE-2021-33560: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-g9p5-p7h5-p2wg
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CVSS 7.5
CWE-203 CWE-325
Published
Advisory Summary

CVE-2021-33560 is a HIGH (CVSS 7.5) security vulnerability vulnerability (CWE-203: Observable Discrepancy) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.. Remediation is available in the latest vendor maintenance releases.

CVE-2021-33560 at a Glance

CVE Identifier CVE-2021-33560
GHSA Identifier GHSA-g9p5-p7h5-p2wg
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-203: Observable Discrepancy
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2021-33560

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2021-33560, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-203: Observable Discrepancy, where the product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm, and the window size is not chosen appropriately. (There is also an interoperability problem because the selection of the k integer value does not properly consider the differences between basic ElGamal encryption and generalized ElGamal encryption.) This, for example, affects use of ElGamal in OpenPGP.

References

NVD — CVE-2021-33560 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-33560
cert-portal.siemens.com/productcert/html/ss... WEB
https://cert-portal.siemens.com/productcert/html/ssa-398330.html
dev.gnupg.org/t5305 WEB
https://dev.gnupg.org/T5305
dev.gnupg.org/t5328 WEB
https://dev.gnupg.org/T5328
dev.gnupg.org/t5466 WEB
https://dev.gnupg.org/T5466
dev.gnupg.org/rce8b7f10be275bcedb... WEB
https://dev.gnupg.org/rCe8b7f10be275bcedb5fc05ed4837a89bfd605c61
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2021/06/msg00021.html
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BKKTOIGFW2SGN3DO2UHHVZ7MJSYN4AAB
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R7OAPCUGPF3VLA7QAJUQSL255D4ITVTL
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BKKTOIGFW2SGN3DO2UHHVZ7MJSYN4AAB
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/R7OAPCUGPF3VLA7QAJUQSL255D4ITVTL
Software Security Information SECURITY
https://security.gentoo.org/glsa/202210-13
Software Security Information SECURITY
https://www.oracle.com/security-alerts/cpuapr2022.html
Software Security Information SECURITY
https://www.oracle.com/security-alerts/cpujan2022.html
Software Security Information SECURITY
https://www.oracle.com/security-alerts/cpujul2022.html
Software Security Information SECURITY
https://www.oracle.com/security-alerts/cpuoct2021.html

Frequently Asked Questions

What is CVE-2021-33560?
CVE-2021-33560 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-203: Observable Discrepancy.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2021-33560?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2021-33560?
CVE-2021-33560 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2021-33560?
CVE-2021-33560 is classified under CWE-203: Observable Discrepancy (The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor.).
How can I check Maven dependencies for CVE-2021-33560?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-g9p5-p7h5-p2wg",
  "modified" : "2026-10-14T12:31:19Z",
  "published" : "2022-05-24T19:04:21Z",
  "aliases" : [ "CVE-2021-33560" ],
  "details" : "Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm, and the window size is not chosen appropriately. (There is also an interoperability problem because the selection of the k integer value does not properly consider the differences between basic ElGamal encryption and generalized ElGamal encryption.) This, for example, affects use of ElGamal in OpenPGP.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-33560"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-398330.html"
  }, {
    "type" : "WEB",
    "url" : "https://dev.gnupg.org/T5305"
  }, {
    "type" : "WEB",
    "url" : "https://dev.gnupg.org/T5328"
  }, {
    "type" : "WEB",
    "url" : "https://dev.gnupg.org/T5466"
  }, {
    "type" : "WEB",
    "url" : "https://dev.gnupg.org/rCe8b7f10be275bcedb5fc05ed4837a89bfd605c61"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2021/06/msg00021.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BKKTOIGFW2SGN3DO2UHHVZ7MJSYN4AAB"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R7OAPCUGPF3VLA7QAJUQSL255D4ITVTL"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/BKKTOIGFW2SGN3DO2UHHVZ7MJSYN4AAB"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/R7OAPCUGPF3VLA7QAJUQSL255D4ITVTL"
  }, {
    "type" : "WEB",
    "url" : "https://security.gentoo.org/glsa/202210-13"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuapr2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujan2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpujul2022.html"
  }, {
    "type" : "WEB",
    "url" : "https://www.oracle.com/security-alerts/cpuoct2021.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-203", "CWE-325" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2021-06-08T11:15:00Z"
  }
}