Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-jx7c-7mj5-9438
Advisory ID github_osv/GHSA-jx7c-7mj5-9438
Aliases CVE-2021-43980
Summary Apache Tomcat Race Condition vulnerability The simplified implementation of blocking reads and writes introduced in Tomcat 10 and back-ported to Tomcat 9.0.47 onwards exposed a long standing (but extremely hard to trigger) concurrency bug in Apache Tomcat 10.1.0 to 10.1.0-M12, 10.0.0-M1 to 10.0.18, 9.0.0-M1 to 9.0.60 and 8.5.0 to 8.5.77 that could cause client connections to share an Http11Processor instance resulting in responses, or part responses, to be received by the wrong client.
Status Published
Exploitability 0.5
Weighted Severity 3.3
Risk 1.6
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (1)
CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
System Score Found at
cvssv3.1 3.7 https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2022/09/GHSA-jx7c-7mj5-9438/GHSA-jx7c-7mj5-9438.json
generic_textual LOW
Reference id Reference type URL
https://github.com/apache/tomcat
https://github.com/apache/tomcat/commit/170e0f792bd18ff031677890ba2fe50eb7a376c1
https://github.com/apache/tomcat/commit/17f177eeb7df5938f67ef9ea580411b120195f13
https://github.com/apache/tomcat/commit/4a00b0c0890538b9d3107eef8f2e0afadd119beb
https://github.com/apache/tomcat/commit/9651b83a1d04583791525e5f0c4c9089f678d9fc
https://tomcat.apache.org/security-10.html
https://tomcat.apache.org/security-8.html
https://tomcat.apache.org/security-9.html
1 Mailing List http://www.openwall.com/lists/oss-security/2022/09/28/1
3jjqbsp6j88b198x5rmg99b1qr8ht3g3 Other https://lists.apache.org/thread/3jjqbsp6j88b198x5rmg99b1qr8ht3g3
CVE-2021-43980 https://nvd.nist.gov/vuln/detail/CVE-2021-43980
dsa-5265 Advisory https://www.debian.org/security/2022/dsa-5265
msg00029.html Mailing List https://lists.debian.org/debian-lts-announce/2022/10/msg00029.html
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2022/09/GHSA-jx7c-7mj5-9438/GHSA-jx7c-7mj5-9438.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2025-05-21T14:59:33Z/

Decision: Track

Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2021/43xxx/CVE-2021-43980.json

Source Advisory: vulnrichment/CVE-2021-43980

View SSVC decision tree 
[{'Exploitation': 'none'},
 {'Automatable': 'no'},
 {'Technical Impact': 'partial'},
 {'Mission Prevalence': 'minimal'},
 {'Public Well-being Impact': 'material'},
 {'Mission & Well-being': 'medium'}]