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Fencer Vulns
low 3.7

CVE-2020-9488 json

Improper validation of certificate with host mismatch in Apache Log4j SMTP appender

published 2020-04-27 6 y ago modified 2026-06-17 4 mo ago also GHSA-vwqq-5vrc-xw9h , EUVD-2020-0518

cvss
3.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
8.2%
EPSS 8.2% chance of exploitation in 30 days, percentile 94%
public exploits
0
none known

Summary

Improper validation of certificate with host mismatch in Apache Log4j SMTP appender. This could allow an SMTPS connection to be intercepted by a man-in-the-middle attack which could leak any log messages sent through that appender. Fixed in Apache Log4j 2.12.3 and 2.13.1

Patch / fix

  • maven org.apache.logging.log4j:log4j 2.3.2, 2.12.3, 2.13.2
  • maven org.apache.logging.log4j:log4j-core 2.3.2, 2.12.3, 2.13.2
  • Apache Apache Log4j 2.12.3
  • apache-log4j2 Debian 14, Debian 13, Debian 12 2.13.3-1

debian advisories DEBIAN-CVE-2020-9488

  • apache-log4j2 Ubuntu 20.04 LTS 2.16.0-0.20.04.1

ubuntu advisories UBUNTU-CVE-2020-9488

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • qpid-cpp a mq clients 2 1.36.0-31.el6_10amq
  • qpid-cpp a mq clients 2 1.36.0-31.el7amq
  • nodejs-rhea a mq clients 2 1.0.24-1.el8
  • qpid-proton a mq clients 2 0.32.0-1.el6_10
  • qpid-proton a mq clients 2 0.32.0-2.el7
  • qpid-proton a mq clients 2 0.32.0-2.el8
  • qpid-proton-c a mq clients 2 0.32.0-1.el6_10
  • qpid-proton-c a mq clients 2 0.32.0-2.el7

red hat advisories RHSA-2020:3817

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-9488 updated cvss 3.7

log4j: improper validation of certificate with host mismatch in SMTP appender

  • Red Hat AMQ Broker 7 log4j
    affected: workaround, no fix available “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.”
  • Red Hat BPM Suite 6 log4j Red Hat Enterprise Linux 5 log4j Red Hat Enterprise Linux 6 log4j, log4j-manual, log4j-javadoc
    affected: workaround, no fix planned “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.”
  • Red Hat Enterprise Linux 7 log4j, log4j-manual, log4j-javadoc Red Hat Enterprise Linux 8 log4j12, log4j12-javadoc
    affected: workaround, no fix available “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.”
  • Red Hat JBoss A-MQ 6 log4j Red Hat JBoss BRMS 5 log4j Red Hat JBoss BRMS 6 log4j Red Hat JBoss Enterprise Application Platform 5 log4j-core Red Hat JBoss Enterprise Application Platform 6 log4j Red Hat JBoss Fuse 6 log4j
    +4 more products
    Red Hat JBoss Fuse Service Works 6 log4j Red Hat JBoss Operations Network 3 log4j Red Hat JBoss SOA Platform 5 log4j Red Hat JBoss Web Server 3 log4j-eap6 log4j-eap6
    affected: workaround, no fix planned “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.”
  • Red Hat OpenShift Container Platform 3.11 openshift3/ose-logging-elasticsearch5 Red Hat OpenShift Container Platform 4 openshift4/ose-metering-hive, openshift4/ose-logging-elasticsearch5
    affected: workaround, no fix available “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.”
  • Red Hat Satellite 5 nutch
    affected: workaround, no fix planned “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.”
  • Red Hat Software Collections rh-maven35-log4j12, rh-maven36-log4j12, rh-java-common-log4j, rh-maven35-log4j12-javadoc, rh-maven36-log4j12-javadoc, rh-java-common-log4j-manual, +1 more
    affected: workaround, no fix available, no fix planned “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.”
  • Red Hat streams for Apache Kafka log4j
    affected: workaround, no fix available “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.”
show 11 more
  • Red Hat AMQ Clients 2 nodejs-rhea 1.0.24-1.el8, qpid-proton 0.32.0-2.el7, qpid-proton 0.32.0-2.el8, qpid-cpp 1.36.0-31.el7amq, qpid-proton-c 0.32.0-2.el7, qpid-proton-c 0.32.0-2.el8, +16 more
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2020:3817
  • Red Hat Data Grid
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2020:3626
  • Red Hat Data Grid 7.3.7
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2020:3779
  • Red Hat Fuse 7.8.0
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2020:5568
  • Red Hat Fuse 7.10
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2021:5134
  • Red Hat JBoss Data Virtualization 6.4.8.SP1
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2022:0497
  • Red Hat JBoss Data Virtualization 6.4.8.SP2
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2022:0507
  • Red Hat RHDM 7.10.0
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2021:0603
  • Red Hat RHPAM 7.10.1
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2021:1044
  • Red Hat Text-Only RHOAR
    fixed: vendor fix “Previous versions can set the system property mail.smtp.ssl.checkserveridentity to true to globally enable hostname verification for SMTPS connections.” RHSA-2020:2391
  • Red Hat JBoss Enterprise Application Platform 7 log4j Red Hat JBoss Enterprise Application Platform Continuous Delivery log4j Red Hat Satellite 6 log4j-over-slf4j Red Hat Single Sign-On 7 log4j
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

8.22% chance of exploitation in the next 30 days, higher than 94% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CNA 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N
GitHub 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
maven org.apache.logging.log4j:log4j
>=2.13.0, <2.13.2
>=2.4.0, <2.12.3
<2.3.2
2.13.2
2.12.3
2.3.2
maven org.apache.logging.log4j:log4j-core
>=2.13.0, <2.13.2
>=2.4.0, <2.12.3
<2.3.2
2.13.2
2.12.3
2.3.2

Affected products

  • Apache Apache Log4j

Classification

Weakness
  • CWE-295 Improper Certificate Validation
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.