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Vulnerability record · CVE-2021-29425 · published 13 April 2021

CVE-2021-29425: Apache commons io improper input validation vulnerability

Apache · Commons Io

In Apache Commons IO before 2.7, When invoking the method FileNameUtils.normalize with an improper input string, like "//../foo", or "\\..\foo", the result would be the same value, thus possibly providing access to files in the parent directory, but not further above (thus "limited" path traversal), if the calling code would use the result to construct a path value.

4.8 CVSS 3.1 Medium EPSS 9.9% · top 4.6% CWE-20 · Improper input validationCWE-22 · Path traversal
4.8CVSS 3.1 base score, v2 5.8
9.9%EPSS exploitation probability, 30 days
NoNot in CISA KEV
60Affected product versions listed by NVD
94References, 2 tagged exploit
25 Aug 2026Last modified by NVD

Description

In Apache Commons IO before 2.7, When invoking the method FileNameUtils.normalize with an improper input string, like "//../foo", or "\\..\foo", the result would be the same value, thus possibly providing access to files in the parent directory, but not further above (thus "limited" path traversal), if the calling code would use the result to construct a path value.

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

Affected products

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

References

LinkTags
https://issues.apache.org/jira/browse/IO-556 ExploitIssue TrackingVendor Advisory
https://lists.apache.org/thread.html/r01b4a1fcdf3311c936ce33d75a9398b6c255f00c1a2f312ac21effe1%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/r0bfa8f7921abdfae788b1f076a12f73a92c93cc0a6e1083bce0027c5%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/r0d73e2071d1f1afe1a15da14c5b6feb2cf17e3871168d5a3c8451436%40%3Ccommits.pulsar.apach
https://lists.apache.org/thread.html/r1c2f4683c35696cf6f863e3c107e37ec41305b1930dd40c17260de71%40%3Ccommits.pulsar.apach
https://lists.apache.org/thread.html/r20416f39ca7f7344e7d76fe4d7063bb1d91ad106926626e7e83fb346%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/r2345b49dbffa8a5c3c589c082fe39228a2c1d14f11b96c523da701db%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/r2721aba31a8562639c4b937150897e24f78f747cdbda8641c0f659fe%40%3Cusers.kafka.apache.o
https://lists.apache.org/thread.html/r27b1eedda37468256c4bb768fde1e8b79b37ec975cbbfd0d65a7ac34%40%3Cdev.myfaces.apache.o
https://lists.apache.org/thread.html/r2bc986a070457daca457a54fe71ee09d2584c24dc262336ca32b6a19%40%3Cdev.creadur.apache.o
https://lists.apache.org/thread.html/r2df50af2641d38f432ef025cd2ba5858215cc0cf3fc10396a674ad2e%40%3Cpluto-scm.portals.ap
https://lists.apache.org/thread.html/r345330b7858304938b7b8029d02537a116d75265a598c98fa333504a%40%3Cdev.creadur.apache.o
https://lists.apache.org/thread.html/r4050f9f6b42ebfa47a98cbdee4aabed4bb5fb8093db7dbb88faceba2%40%3Ccommits.zookeeper.ap
https://lists.apache.org/thread.html/r462db908acc1e37c455e11b1a25992b81efd18e641e7e0ceb1b6e046%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/r477c285126ada5c3b47946bb702cb222ac4e7fd3100c8549bdd6d3b2%40%3Cissues.zookeeper.apa
https://lists.apache.org/thread.html/r47ab6f68cbba8e730f42c4ea752f3a44eb95fb09064070f2476bb401%40%3Cdev.creadur.apache.o
https://lists.apache.org/thread.html/r5149f78be265be69d34eacb4e4b0fc7c9c697bcdfa91a1c1658d717b%40%3Cissues.zookeeper.apa
https://lists.apache.org/thread.html/r523a6ffad58f71c4f3761e3cee72df878e48cdc89ebdce933be1475c%40%3Cdev.creadur.apache.o
https://lists.apache.org/thread.html/r808be7d93b17a7055c1981a8453ae5f0d0fce5855407793c5d0ffffa%40%3Cuser.commons.apache.
https://lists.apache.org/thread.html/r8569a41d565ca880a4dee0e645dad1cd17ab4a92e68055ad9ebb7375%40%3Cdev.creadur.apache.o
https://lists.apache.org/thread.html/r86528f4b7d222aed7891e7ac03d69a0db2a2dfa17b86ac3470d7f374%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/r873d5ddafc0a68fd999725e559776dc4971d1ab39c0f5cc81bd9bc04%40%3Ccommits.pulsar.apach
https://lists.apache.org/thread.html/r8bfc7235e6b39d90e6f446325a5a44c3e9e50da18860fdabcee23e29%40%3Cissues.zookeeper.apa
https://lists.apache.org/thread.html/r8efcbabde973ea72f5e0933adc48ef1425db5cde850bf641b3993f31%40%3Cdev.commons.apache.o
https://lists.apache.org/thread.html/r92ea904f4bae190b03bd42a4355ce3c2fbe8f36ab673e03f6ca3f9fa%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/ra8ef65aedc086d2d3d21492b4c08ae0eb8a3a42cc52e29ba1bc009d8%40%3Cdev.creadur.apache.o
https://lists.apache.org/thread.html/raa053846cae9d497606027816ae87b4e002b2e0eb66cb0dee710e1f5%40%3Cdev.creadur.apache.o
https://lists.apache.org/thread.html/rad4ae544747df32ccd58fff5a86cd556640396aeb161aa71dd3d192a%40%3Cuser.commons.apache.
https://lists.apache.org/thread.html/rbebd3e19651baa7a4a5503a9901c95989df9d40602c8e35cb05d3eb5%40%3Cdev.creadur.apache.o
https://lists.apache.org/thread.html/rc10fa20ef4d13cbf6ebe0b06b5edb95466a1424a9b7673074ed03260%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/rc2dd3204260e9227a67253ef68b6f1599446005bfa0e1ddce4573a80%40%3Cpluto-dev.portals.ap
https://lists.apache.org/thread.html/rc359823b5500e9a9a2572678ddb8e01d3505a7ffcadfa8d13b8780ab%40%3Cuser.commons.apache. Mailing ListVendor Advisory
https://lists.apache.org/thread.html/rc5f3df5316c5237b78a3dff5ab95b311ad08e61d418cd992ca7e34ae%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/rc65f9bc679feffe4589ea0981ee98bc0af9139470f077a91580eeee0%40%3Cpluto-dev.portals.ap
https://lists.apache.org/thread.html/rca71a10ca533eb9bfac2d590533f02e6fb9064d3b6aa3ec90fdc4f51%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/rd09d4ab3e32e4b3a480e2ff6ff118712981ca82e817f28f2a85652a6%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/re41e9967bee064e7369411c28f0f5b2ad28b8334907c9c6208017279%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/red3aea910403d8620c73e1c7b9c9b145798d0469eb3298a7be7891af%40%3Cnotifications.zookee
https://lists.apache.org/thread.html/rfa2f08b7c0caf80ca9f4a18bd875918fdd4e894e2ea47942a4589b9c%40%3Cdev.creadur.apache.o
https://lists.apache.org/thread.html/rfcd2c649c205f12b72dde044f905903460669a220a2eb7e12652d19d%40%3Cdev.zookeeper.apache

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Source: NIST National Vulnerability Database (record CVE-2021-29425), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.