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CVE-2018-0732· NVD / CVE Program· CNA openssl

Client DoS due to large DH parameter

During key agreement in a TLS handshake using a DH(E) based ciphersuite a malicious server can send a very large prime value to the client. This will cause the client to spend an unreasonably long period of time generating a key for this prime resulting in a hang until the client has finished. This could be exploited in a Denial Of Service attack. Fixed in OpenSSL 1.1.0i-dev (Affected 1.1.0-1.1.0h). Fixed in OpenSSL 1.0.2p-dev (Affected 1.0.2-1.0.2o).

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Jun 12, 2018
Updated
Jun 16, 2026
EPSS
48.8% · 99th percentile
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Report tools

JSON

Action score

45

Plan

Add it to your regular patch cycle.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
15 / 30 · 48.8%

Affected systems

VendorProduct
opensslopenssl
canonicalubuntu linux
debiandebian linux
nodejsnode.js

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • nodejs node.js6.0.0 and later · before 6.8.1
  • nodejs node.js6.9.0 and later · before 6.14.4
  • nodejs node.js8.0.0 and later · before 8.8.1
  • nodejs node.js8.9.0 and later · before 8.11.4
  • nodejs node.js10.0.0 and later · before 10.9.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (openssl). Independent of NVD's CPE analysis and usually ahead of it.

  • OpenSSL OpenSSL

    • Fixed in OpenSSL 1.1.0i-dev (Affected 1.1.0-1.1.0h), Fixed in OpenSSL 1.0.2p-dev (Affected 1.0.2-1.0.2o)affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.10libresslbefore 2.7.4-r02.7.4-r0
Alpine:v3.3opensslfrom 1.0.2 · before 1.0.2o-r11.0.2o-r1
Alpine:v3.7libresslbefore 2.6.5-r02.6.5-r0
Debian:12opensslbefore 1.1.1-11.1.1-1
Debian:8opensslbefore 1.0.1t-1+deb8u91.0.1t-1+deb8u9
Debian:9opensslbefore 1.1.0j-1~deb9u11.1.0j-1~deb9u1
Debian:9openssl1.0before 1.0.2q-1~deb9u11.0.2q-1~deb9u1
openSUSE:Tumbleweedopenssl-1_0_0before 1.0.2u-6.21.0.2u-6.2
openSUSE:Tumbleweedvirtualboxbefore 6.1.26-3.26.1.26-3.2
Red Hat:enterprise_linux:7::clientopensslbefore 1:1.0.2k-16.el71:1.0.2k-16.el7
Red Hat:enterprise_linux:7::clientopenssl-debuginfobefore 1:1.0.2k-16.el71:1.0.2k-16.el7
Red Hat:enterprise_linux:7::clientopenssl-develbefore 1:1.0.2k-16.el71:1.0.2k-16.el7
Red Hat:enterprise_linux:7::clientopenssl-libsbefore 1:1.0.2k-16.el71:1.0.2k-16.el7
Red Hat:enterprise_linux:7::clientopenssl-perlbefore 1:1.0.2k-16.el71:1.0.2k-16.el7
Red Hat:enterprise_linux:7::clientopenssl-staticbefore 1:1.0.2k-16.el71:1.0.2k-16.el7
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpdbefore 0:2.4.29-40.jbcs.el60:2.4.29-40.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpd-debuginfobefore 0:2.4.29-40.jbcs.el60:2.4.29-40.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpd-develbefore 0:2.4.29-40.jbcs.el60:2.4.29-40.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpd-manualbefore 0:2.4.29-40.jbcs.el60:2.4.29-40.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpd-selinuxbefore 0:2.4.29-40.jbcs.el60:2.4.29-40.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-httpd-toolsbefore 0:2.4.29-40.jbcs.el60:2.4.29-40.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-mod_ldapbefore 0:2.4.29-40.jbcs.el60:2.4.29-40.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-mod_proxy_htmlbefore 1:2.4.29-40.jbcs.el61:2.4.29-40.jbcs.el6
Red Hat:jboss_core_services:1::el6jbcs-httpd24-mod_sessionbefore 0:2.4.29-40.jbcs.el60:2.4.29-40.jbcs.el6

+46

Other highest-scoring records for the same primary product.

  • CVE-2014-0160The (1) TLS and (2) DTLS implementations in OpenSSL 1.0.1 before 1.0.1g do not properly handle Heartbeat Extension packets, which allows remKEV
    90Now
  • CVE-2021-3711SM2 Decryption Buffer Overflow
    65This week
  • CVE-2003-0545Double free vulnerability in OpenSSL 0.9.7 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code
    65This week
  • CVE-2016-2108The ASN.1 implementation in OpenSSL before 1.0.1o and 1.0.2 before 1.0.2c allows remote attackers to execute arbitrary code or cause a denia
    62This week
  • CVE-2016-6309statem/statem.c in OpenSSL 1.1.0a does not consider memory-block movement after a realloc call, which allows remote attackers to cause a den
    60This week
  • CVE-2022-3786X.509 Email Address Variable Length Buffer Overflow
    58Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:libressl2.7.4-r0 · Alpine:v3.10Package registry (OSV)
alpine:openssl1.0.2o-r1 · Alpine:v3.3Package registry (OSV)
debian:openssl1.1.1-1 · Debian:12Package registry (OSV)
debian:openssl1.01.0.2q-1~deb9u1 · Debian:9Package registry (OSV)
opensuse:openssl-1_0_01.0.2u-6.2 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:virtualbox6.1.26-3.2 · openSUSE:TumbleweedPackage registry (OSV)
red hat:jbcs-httpd24-httpd0:2.4.29-40.jbcs.el6 · Red Hat:jboss_core_services:1::el6Package registry (OSV)
red hat:jbcs-httpd24-httpd-debuginfo0:2.4.29-40.jbcs.el6 · Red Hat:jboss_core_services:1::el6Package registry (OSV)
red hat:npm1:5.6.0-1.8.11.4.2.el7 · Red Hat:openshift_application_runtimes:1.0::el7Package registry (OSV)
red hat:openssl1:1.0.2k-16.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:openssl-debuginfo1:1.0.2k-16.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:openssl-devel1:1.0.2k-16.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:openssl-libs1:1.0.2k-16.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:openssl-perl1:1.0.2k-16.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:openssl-static1:1.0.2k-16.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:rhoar-nodejs1:8.11.4-2.el7 · Red Hat:openshift_application_runtimes:1.0::el7Package registry (OSV)
red hat:rhoar-nodejs-debuginfo1:8.11.4-2.el7 · Red Hat:openshift_application_runtimes:1.0::el7Package registry (OSV)
red hat:rhoar-nodejs-docs1:8.11.4-2.el7 · Red Hat:openshift_application_runtimes:1.0::el7Package registry (OSV)
suse:compat-openssl097g0.9.7g-146.22.51.5.1 · SUSE:Linux Enterprise Server for SAP Applications 11 SP4Package registry (OSV)
suse:compat-openssl0980.9.8j-106.6.1 · SUSE:Linux Enterprise Desktop 12 SP3Package registry (OSV)
suse:nodejs44.9.1-15.14.1 · SUSE:Linux Enterprise Module for Web and Scripting 12Package registry (OSV)
suse:nodejs66.14.4-11.18.1 · SUSE:OpenStack Cloud 7Package registry (OSV)
suse:nodejs88.11.4-3.8.2 · SUSE:Linux Enterprise Module for Web and Scripting 15Package registry (OSV)
suse:openssl1.0.2j-60.30.1 · SUSE:OpenStack Cloud 7Package registry (OSV)
suse:openssl-1_0_01.0.2n-3.3.1 · SUSE:Linux Enterprise Module for Legacy 15Package registry (OSV)
suse:openssl-1_11.1.0h-4.3.1 · SUSE:Linux Enterprise Module for Basesystem 15Package registry (OSV)
suse:openssl11.0.1g-0.58.12.1 · SUSE:Linux Enterprise Server 11-SECURITYPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

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Change log

  1. Fix✗ → ✓

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References

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