CVE-2004-0940: Buffer overflow in the get_tag function in mod_include for Apache 1.3.x to 1.3.32 allows local users who can c

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HIGH 7.8WATCHLISTUPGRADEDOWNGRADEMITIGATE

CVE-2004-0940 is a high-severity flaw (CVSS 7.8) affecting http server, openpkg, hp-ux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the get_tag function in mod_include for Apache 1.3.x to 1.3.32 allows local users who can create SSI documents to execute arbitrary code as the apache user via SSI (XSSI) documents that trigger a length calculation error.

Why this priority

High severity
EPSS top 8%: very likely to be exploited
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	4.8% (top 8%)
CISA exploited list	No
Weakness	CWE-131
Published	2005-02-09
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: apache · hp · openpkg · slackware · suse · trustix

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

Am I affected?

Timeline

2005-02-09 05:00 UTCPublished CVE record published
2026-06-16 22:06 UTCUpdated Record last modified

apache http server UPGRADE

Affected: >= 1.3 and <= 1.3.32

Fixed in: newer than 1.3.32

Safe to downgrade to: a release before 1.3

1. Check installed version

apt-cache policy http-server || rpm -q http-server || http-server --version

2. UPGRADE to newer than 1.3.32 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade http-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade http-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 1.3 (Debian / Ubuntu)

apt-cache madison http-server sudo apt install http-server=<VERSION_BEFORE_1.3> sudo apt-mark hold http-server

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list http-server sudo dnf downgrade http-server-<VERSION_BEFORE_1.3> sudo dnf versionlock add http-server

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.

openpkg openpkg DOWNGRADE

Affected: 2.0 · 2.1 · 2.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.0 (Debian / Ubuntu)

apt-cache madison openpkg sudo apt install openpkg=<VERSION_BEFORE_2.0> sudo apt-mark hold openpkg

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

dnf --showduplicates list openpkg sudo dnf downgrade openpkg-<VERSION_BEFORE_2.0> sudo dnf versionlock add openpkg

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.

hp hp-ux MITIGATE

Affected: 11.00 · 11.11 · 11.20 · 11.22

Fixed in: no fixed release known

Safe to downgrade to: a release before 11.00

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.

slackware slackware linux MITIGATE

Affected: 8.0 · 8.1 · 9.0 · 9.1 · 10.0 · current

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

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.

suse suse linux MITIGATE

Affected: 8.0 · 8.1 · 8.2 · 9.0 · 9.1 · 9.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

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.

trustix secure linux MITIGATE

Affected: 1.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.5

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: Apache 1.3.31 mod_include - Local Buffer Overflow
Exploit-DB: Apache 1.3.x mod_include - Local Buffer 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-2004-0940?

http server: upgrade to newer than 1.3.32; openpkg: downgrade or apply the listed mitigation; hp-ux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2004-0940 being exploited?

CVE-2004-0940 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-2004-0940 affect?

CVE-2004-0940 affects http server, openpkg, hp-ux. Severity is high (CVSS 7.8). Buffer overflow in the get_tag function in mod_include for Apache 1.3.x to 1.3.32 allows local users who can create SSI documents to execute arbitrary code as the apache user via SSI (XSSI) documents that trigger a length calculation error.

How urgent is CVE-2004-0940?

Priority 60/100. High severity; EPSS top 8%: very likely to be exploited; Public exploit reference; On your watchlist

Software pages

Apache HTTP Server vulnerabilities

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References

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