CVE-2005-4784: Multiple buffer overflows in the POSIX readdir_r function, as used in multiple packages, allow local users to

Routine

MEDIUM 5.6MITIGATE

CVE-2005-4784 is a medium-severity flaw (CVSS 5.6) affecting posix. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Multiple buffer overflows in the POSIX readdir_r function, as used in multiple packages, allow local users to cause a denial of service and possibly execute arbitrary code via (1) a symlink attack that exploits a race condition between opendir and pathcon calls and changes the filesystem to one with a larger maximum directory-entry name length, or (2) possibly via programmer-introduced errors on operating systems with a small struct dirent, such

Why this priority

No elevated risk signals yet

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.6 (Medium)
EPSS exploit chance	0.4% (top 62%)
CISA exploited list	No
Published	2005-12-31
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: austin group

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2005-12-31 05:00 UTCPublished CVE record published
2026-06-16 22:19 UTCUpdated Record last modified

austin group posix MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2005-4784?

posix: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2005-4784 being exploited?

CVE-2005-4784 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2005-4784 affect?

CVE-2005-4784 affects posix. Severity is medium (CVSS 5.6). Multiple buffer overflows in the POSIX readdir_r function, as used in multiple packages, allow local users to cause a denial of service and possibly execute arbitrary code via (1) a symlink attack that exploits a race condition between open

How urgent is CVE-2005-4784?

Priority 29/100. No elevated risk signals yet.

Related CVEs

CVE-2022-21211 MEDIUM 5.9 MITIGATE This affects all versions of package posix

References

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