CVE-2004-0947: Buffer overflow in unarj before 2.63a-r2 allows remote attackers to execute arbitrary code via an arj archive

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HIGH 10.0WATCHLISTDOWNGRADEMITIGATEMITIGATE

CVE-2004-0947 is a high-severity flaw (CVSS 10.0) affecting unarj, linux, suse linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in unarj before 2.63a-r2 allows remote attackers to execute arbitrary code via an arj archive that contains long filenames.

Why this priority

Critical severity
EPSS top 6%: very likely to be exploited
On your watchlist

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

Risk facts

CVSS score	10.0 (High)
EPSS exploit chance	7.4% (top 6%)
CISA exploited list	No
Published	2005-02-09
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: arj software inc. · gentoo · suse

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

arj software inc. unarj DOWNGRADE

Affected: 2.62 · 2.63_a · 2.64 · 2.65

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.62

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 2.62 (Debian / Ubuntu)

apt-cache madison unarj sudo apt install unarj=<VERSION_BEFORE_2.62> sudo apt-mark hold unarj

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

dnf --showduplicates list unarj sudo dnf downgrade unarj-<VERSION_BEFORE_2.62> sudo dnf versionlock add unarj

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.

gentoo linux 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.

suse suse linux MITIGATE

Affected: 9.0 · 9.1 · 9.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

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.

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-2004-0947?

unarj: downgrade or apply the listed mitigation; linux: mitigate or apply the listed mitigation; suse linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2004-0947 being exploited?

CVE-2004-0947 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-2004-0947 affect?

CVE-2004-0947 affects unarj, linux, suse linux. Severity is high (CVSS 10.0). Buffer overflow in unarj before 2.63a-r2 allows remote attackers to execute arbitrary code via an arj archive that contains long filenames.

How urgent is CVE-2004-0947?

Priority 64/100. Critical severity; EPSS top 6%: very likely to be exploited; On your watchlist

Related CVEs

CVE-2004-1027 MEDIUM 5.0 DOWNGRADE MITIGATE Directory traversal vulnerability in the -x (extract) command line option in unarj allows remote attackers to

References

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