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Vulnerability record · CVE-2021-35940 · published 23 August 2021

CVE-2021-35940: Apache portable runtime out-of-bounds read vulnerability

Apache · Portable Runtime

An out-of-bounds array read in the apr_time_exp*() functions was fixed in the Apache Portable Runtime 1.6.3 release (CVE-2017-12613). The fix for this issue was not carried forward to the APR 1.7.x branch, and hence version 1.7.0 regressed compared to 1.6.3 and is vulnerable to the same issue.

7.1 CVSS 3.1 High EPSS 1.2% · top 33.4% CWE-125 · Out-of-bounds read
7.1CVSS 3.1 base score, v2 3.6
1.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
38References
17 Jun 2026Last modified by NVD

Description

An out-of-bounds array read in the apr_time_exp*() functions was fixed in the Apache Portable Runtime 1.6.3 release (CVE-2017-12613). The fix for this issue was not carried forward to the APR 1.7.x branch, and hence version 1.7.0 regressed compared to 1.6.3 and is vulnerable to the same issue.

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

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://mail-archives.apache.org/mod_mbox/www-announce/201710.mbox/%3CCACsi251B8UaLvM-rrH9fv57-zWi0zhyF3275_jPg1a9VEVVoxw
http://svn.apache.org/viewvc?view=revision&revision=1891198 Vendor Advisory
http://www.openwall.com/lists/oss-security/2021/08/23/1 Mailing ListThird Party Advisory
https://dist.apache.org/repos/dist/release/apr/patches/apr-1.7.0-CVE-2021-35940.patch PatchVendor Advisory
https://lists.apache.org/thread.html/r1c788464a25fbc046a72aff451bc8186386315d92a2dd0349903fa4f%40%3Cdev.tomcat.apache.or
https://lists.apache.org/thread.html/r317c398ee5736e627f7887b06607e5c58b45a696d352ba8c14615f55%40%3Cdev.apr.apache.org%3
https://lists.apache.org/thread.html/r54c755c74b9e3846cfd84039b1967d37d2870750a02d7c603983f6ed%40%3Cdev.tomcat.apache.or
https://lists.apache.org/thread.html/r72479f4dcffaa8a4732d5a0e87fecc4bace4932e28fc26f7d400e2b3%40%3Cdev.tomcat.apache.or
https://lists.apache.org/thread.html/r72a069753b9363c29732e59ad8f0d22a633fb6a699980407511ac961%40%3Cdev.apr.apache.org%3
https://lists.apache.org/thread.html/r7bb4a6ed88fc48152174e664aae30ea9a8b058eb5b44cf08cb9beb4b%40%3Cdev.apr.apache.org%3
https://lists.apache.org/thread.html/r7bb4a6ed88fc48152174e664aae30ea9a8b058eb5b44cf08cb9beb4b%40%3Cdev.httpd.apache.org
https://lists.apache.org/thread.html/ra2868b53339a6af65577146ad87016368c138388b09bff9d2860f50e%40%3Cdev.apr.apache.org%3 Mailing ListVendor Advisory
https://lists.apache.org/thread.html/ra2868b53339a6af65577146ad87016368c138388b09bff9d2860f50e%40%3Cdev.apr.apache.org%3 Mailing ListVendor Advisory
https://lists.apache.org/thread.html/ra2868b53339a6af65577146ad87016368c138388b09bff9d2860f50e%40%3Cdev.apr.apache.org%3 Mailing ListVendor Advisory
https://lists.apache.org/thread.html/ra2868b53339a6af65577146ad87016368c138388b09bff9d2860f50e%40%3Cdev.apr.apache.org%3 Mailing ListVendor Advisory
https://lists.apache.org/thread.html/ra38094406cc38a05218ebd1158187feda021b0c3a1df400bbf296af8%40%3Cdev.apr.apache.org%3
https://lists.apache.org/thread.html/rafe54755850e93de287c36540972457b2dd86332106aa7817c7c27fb%40%3Cdev.tomcat.apache.or
https://lists.apache.org/thread.html/rb1f3c85f50fbd924a0051675118d1609e57957a02ece7facb723155b%40%3Cannounce.apache.org%
https://www.oracle.com/security-alerts/cpujul2022.html PatchThird Party Advisory
http://mail-archives.apache.org/mod_mbox/www-announce/201710.mbox/%3CCACsi251B8UaLvM-rrH9fv57-zWi0zhyF3275_jPg1a9VEVVoxw
http://svn.apache.org/viewvc?view=revision&revision=1891198 Vendor Advisory
http://www.openwall.com/lists/oss-security/2021/08/23/1 Mailing ListThird Party Advisory
https://dist.apache.org/repos/dist/release/apr/patches/apr-1.7.0-CVE-2021-35940.patch PatchVendor Advisory
https://lists.apache.org/thread.html/r1c788464a25fbc046a72aff451bc8186386315d92a2dd0349903fa4f%40%3Cdev.tomcat.apache.or
https://lists.apache.org/thread.html/r317c398ee5736e627f7887b06607e5c58b45a696d352ba8c14615f55%40%3Cdev.apr.apache.org%3
https://lists.apache.org/thread.html/r54c755c74b9e3846cfd84039b1967d37d2870750a02d7c603983f6ed%40%3Cdev.tomcat.apache.or
https://lists.apache.org/thread.html/r72479f4dcffaa8a4732d5a0e87fecc4bace4932e28fc26f7d400e2b3%40%3Cdev.tomcat.apache.or
https://lists.apache.org/thread.html/r72a069753b9363c29732e59ad8f0d22a633fb6a699980407511ac961%40%3Cdev.apr.apache.org%3
https://lists.apache.org/thread.html/r7bb4a6ed88fc48152174e664aae30ea9a8b058eb5b44cf08cb9beb4b%40%3Cdev.apr.apache.org%3
https://lists.apache.org/thread.html/r7bb4a6ed88fc48152174e664aae30ea9a8b058eb5b44cf08cb9beb4b%40%3Cdev.httpd.apache.org
https://lists.apache.org/thread.html/ra2868b53339a6af65577146ad87016368c138388b09bff9d2860f50e%40%3Cdev.apr.apache.org%3 Mailing ListVendor Advisory
https://lists.apache.org/thread.html/ra2868b53339a6af65577146ad87016368c138388b09bff9d2860f50e%40%3Cdev.apr.apache.org%3 Mailing ListVendor Advisory
https://lists.apache.org/thread.html/ra2868b53339a6af65577146ad87016368c138388b09bff9d2860f50e%40%3Cdev.apr.apache.org%3 Mailing ListVendor Advisory
https://lists.apache.org/thread.html/ra2868b53339a6af65577146ad87016368c138388b09bff9d2860f50e%40%3Cdev.apr.apache.org%3 Mailing ListVendor Advisory
https://lists.apache.org/thread.html/ra38094406cc38a05218ebd1158187feda021b0c3a1df400bbf296af8%40%3Cdev.apr.apache.org%3
https://lists.apache.org/thread.html/rafe54755850e93de287c36540972457b2dd86332106aa7817c7c27fb%40%3Cdev.tomcat.apache.or
https://lists.apache.org/thread.html/rb1f3c85f50fbd924a0051675118d1609e57957a02ece7facb723155b%40%3Cannounce.apache.org%
https://www.oracle.com/security-alerts/cpujul2022.html PatchThird Party Advisory

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Source: NIST National Vulnerability Database (record CVE-2021-35940), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.