CVE-2004-0649: Buffer overflow in write_packet in control.c for l2tpd may allow remote attackers to execute arbitrary code.

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HIGH 10.0WATCHLISTDOWNGRADEMITIGATE

CVE-2004-0649 is a high-severity flaw (CVSS 10.0) affecting l2tpd, linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in write_packet in control.c for l2tpd may allow remote attackers to execute arbitrary code.

Why this priority

Critical severity
EPSS top 8%: 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	5.2% (top 8%)
CISA exploited list	No
Published	2004-08-06
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: gentoo · l2tpd

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

Am I affected?

Timeline

2004-08-06 04:00 UTCPublished CVE record published
2026-06-16 22:06 UTCUpdated Record last modified

l2tpd l2tpd DOWNGRADE

Affected: 0.62 · 0.63 · 0.64 · 0.65 · 0.66 · 0.67 · 0.68 · 0.69

Fixed in: no fixed release known

Safe to downgrade to: a release before 0.62

1. Check installed version

apt-cache policy l2tpd || rpm -q l2tpd || l2tpd --version

2. No fixed release: DOWNGRADE to a release before 0.62 (Debian / Ubuntu)

apt-cache madison l2tpd sudo apt install l2tpd=<VERSION_BEFORE_0.62> sudo apt-mark hold l2tpd

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

dnf --showduplicates list l2tpd sudo dnf downgrade l2tpd-<VERSION_BEFORE_0.62> sudo dnf versionlock add l2tpd

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: 1.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.4

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-2004-0649?

l2tpd: downgrade or apply the listed mitigation; linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2004-0649 being exploited?

CVE-2004-0649 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-2004-0649 affect?

CVE-2004-0649 affects l2tpd, linux. Severity is high (CVSS 10.0). Buffer overflow in write_packet in control.c for l2tpd may allow remote attackers to execute arbitrary code.

How urgent is CVE-2004-0649?

Priority 63/100. Critical severity; EPSS top 8%: very likely to be exploited; On your watchlist

Related CVEs

CVE-2002-0873 MEDIUM 5.0 DOWNGRADE Vulnerability in l2tpd 0.67 allows remote attackers to overwrite the vendor field via a long value in an attri
CVE-2002-0872 HIGH 7.5 DOWNGRADE l2tpd 0.67 does not initialize the random number generator, which allows remote attackers to hijack sessions.

References

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