7.5

CVE-2021-4104: Deserialization of untrusted data in JMSAppender in Apache Log4j 1.2

Modified
AliasesSUSE-SU-2021:14866-1SUSE-SU-2021:4111-1SUSE-SU-2021:4112-1
Published 14-12-2021Last modified 28-05-2026

Vulnerability summary

CVE-2021-4104 is a high (CVSS 7.5) Deserialization of Untrusted Data vulnerability in apache software foundation apache log4j 1.x. EPSS estimates a 80.60% chance of exploitation in the next 30 days, higher than 99.6% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.5, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
80.60%
0%100%
Critical · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 24 · Related 7
DLA-2905-1MGASA-2023-0141OPENSUSE-SU-2022:0038-1OPENSUSE-SU-2024:11681-1RHSA-2022:0289RHSA-2022:0290

Timeline

  1. 14-12-2021
    PublishedVulnerability first disclosed.
  2. 28-05-2026
    Last modifiedVulnerability information updated.

Description

JMSAppender in Log4j 1.2 is vulnerable to deserialization of untrusted data when the attacker has write access to the Log4j configuration. The attacker can provide TopicBindingName and TopicConnectionFactoryBindingName configurations causing JMSAppender to perform JNDI requests that result in remote code execution in a similar fashion to CVE-2021-44228. Note this issue only affects Log4j 1.2 when specifically configured to use JMSAppender, which is not the default. Apache Log4j 1.2 reached end of life in August 2015. Users should upgrade to Log4j 2 as it addresses numerous other issues from the previous versions.

CVSS metrics

9 scores · 8 sources · 2 versions

EPSS trend

Probability

80.60%

Chance of exploitation in the next 30 days

Percentile

100%

Versus all other CVEs

30-day change

No change 0.00 pp

From 80.60% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Suse131 products
  • elasticsearch&distro=HPE Helion OpenStack 8< 2.4.2-5.3.1
  • elasticsearch&distro=SUSE OpenStack Cloud 8< 2.4.2-5.3.1
  • elasticsearch&distro=SUSE OpenStack Cloud 9< 2.4.2-6.3.1
  • elasticsearch&distro=SUSE OpenStack Cloud Crowbar 8< 2.4.2-5.3.1
  • elasticsearch&distro=SUSE OpenStack Cloud Crowbar 9< 2.4.2-6.3.1
Oracle26 products
Redhat24 products
Opensuse7 products
  • kafka-kit&distro=openSUSE Leap 15.3< 2.1.0-bp153.2.3.1
  • kafka-kit&distro=openSUSE Tumbleweed< 2.1.0-2.1
  • kafka&distro=openSUSE Leap 15.3< 2.1.0-bp153.2.3.1
  • log4j12-mini&distro=openSUSE Leap 15.2< 1.2.17-lp152.3.3.2
  • log4j12&distro=openSUSE Leap 15.2< 1.2.17-lp152.3.3.2
Chainguard4 products
  • druid< 35.0.1-r1 | All versions (No fix recorded)
  • hadoop-fips-3.3.6All versions (No fix recorded)
  • hadoop-fips-3.4.2All versions (No fix recorded)
  • hadoop-fips-3.5All versions (No fix recorded)
Apache1 product
Apache software foundation1 product
Debian1 product
  • apache-log4j1.2< 1.2.17-11
Fedoraproject1 product
Log4j1 product
  • log4j≥ 1.2.0, ≤ 1.2.17
Org.zenframework.z8.dependencies.commons1 product
  • log4j-1.2.17≤ 2.0
Ubuntu1 product
  • apache-log4j1.2< 1.2.17-8+deb10u1ubuntu0.1 | < 1.2.17-9ubuntu0.1 | < 1.2.17-7ubuntu1+esm1 | < 1.2.17-4ubuntu3+esm1
Wolfi1 product
  • druid< 35.0.1-r1 | All versions (No fix recorded)

13 vendors · 200 products · Showing 200 of 202

References

47 links
Show all 47 references