CVE-2005-0156: Buffer overflow in the PerlIO implementation in Perl 5.8.0, when installed with setuid support (sperl), allows

Routine

LOW 2.1WATCHLISTDOWNGRADEDOWNGRADEMITIGATE

CVE-2005-0156 is a low-severity flaw (CVSS 2.1) affecting perl, propack, aix. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the PerlIO implementation in Perl 5.8.0, when installed with setuid support (sperl), allows local users to execute arbitrary code by setting the PERLIO_DEBUG variable and executing a Perl script whose full pathname contains a long directory tree.

Why this priority

Public exploit reference
On your watchlist

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

Risk facts

CVSS score	2.1 (Low)
EPSS exploit chance	1.3% (top 29%)
CISA exploited list	No
Published	2005-02-07
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: ibm · larry wall · redhat · sgi

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

Am I affected?

Timeline

2005-02-07 05:00 UTCPublished CVE record published
2026-06-16 22:10 UTCUpdated Record last modified

larry wall perl DOWNGRADE

Affected: 5.8.0 · 5.8.1 · 5.8.3 · 5.8.4 · 5.8.4.1 · 5.8.4.2 · 5.8.4.2.3 · 5.8.4.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.8.0

1. Check installed version

apt-cache policy perl || rpm -q perl || perl --version

2. No fixed release: DOWNGRADE to a release before 5.8.0 (Debian / Ubuntu)

apt-cache madison perl sudo apt install perl=<VERSION_BEFORE_5.8.0> sudo apt-mark hold perl

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list perl sudo dnf downgrade perl-<VERSION_BEFORE_5.8.0> sudo dnf versionlock add perl

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

sgi propack DOWNGRADE

Affected: 3.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0

1. Check installed version

apt-cache policy propack || rpm -q propack || propack --version

2. No fixed release: DOWNGRADE to a release before 3.0 (Debian / Ubuntu)

apt-cache madison propack sudo apt install propack=<VERSION_BEFORE_3.0> sudo apt-mark hold propack

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list propack sudo dnf downgrade propack-<VERSION_BEFORE_3.0> sudo dnf versionlock add propack

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

ibm aix MITIGATE

Affected: 5.2 · 5.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.2

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.

redhat enterprise linux MITIGATE

Affected: 3.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0

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.

redhat enterprise linux desktop MITIGATE

Affected: 3.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0

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.

redhat fedora core MITIGATE

Affected: core_3.0

Fixed in: no fixed release known

Safe to downgrade to: a release before core_3.0

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.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Setuid perl - 'PerlIO_Debug()' Local Overflow

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-2005-0156?

perl: downgrade or apply the listed mitigation; propack: downgrade or apply the listed mitigation; aix: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2005-0156 being exploited?

CVE-2005-0156 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-2005-0156 affect?

CVE-2005-0156 affects perl, propack, aix. Severity is low (CVSS 2.1). Buffer overflow in the PerlIO implementation in Perl 5.8.0, when installed with setuid support (sperl), allows local users to execute arbitrary code by setting the PERLIO_DEBUG variable and executing a Perl script whose full pathname contai

How urgent is CVE-2005-0156?

Priority 35/100. Public exploit reference; On your watchlist

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References

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