CVE-2004-0077: The do_mremap function for the mremap system call in Linux 2.2 to 2.2.25, 2.4 to 2.4.24, and 2.6 to 2.6.2, doe

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HIGH 7.2WATCHLISTDOWNGRADEMITIGATEDOWNGRADE

CVE-2004-0077 is a high-severity flaw (CVSS 7.2) affecting bigmem kernel, kernel, kernel doc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The do_mremap function for the mremap system call in Linux 2.2 to 2.2.25, 2.4 to 2.4.24, and 2.6 to 2.6.2, does not properly check the return value from the do_munmap function when the maximum number of VMA descriptors is exceeded, which allows local users to gain root privileges, a different vulnerability than CAN-2003-0985.

Why this priority

High severity
Public exploit reference
On your watchlist

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

Risk facts

CVSS score	7.2 (High)
EPSS exploit chance	2.5% (top 16%)
CISA exploited list	No
Published	2004-03-03
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: linux · netwosix · redhat

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

Am I affected?

Timeline

2004-03-03 05:00 UTCPublished CVE record published
2026-06-16 22:04 UTCUpdated Record last modified

redhat bigmem kernel DOWNGRADE

Affected: 2.4.20-8

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.4.20-8

1. Check installed version

apt-cache policy bigmem-kernel || rpm -q bigmem-kernel || bigmem-kernel --version

2. No fixed release: DOWNGRADE to a release before 2.4.20-8 (Debian / Ubuntu)

apt-cache madison bigmem-kernel sudo apt install bigmem-kernel=<VERSION_BEFORE_2.4.20-8> sudo apt-mark hold bigmem-kernel

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

dnf --showduplicates list bigmem-kernel sudo dnf downgrade bigmem-kernel-<VERSION_BEFORE_2.4.20-8> sudo dnf versionlock add bigmem-kernel

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.

redhat kernel MITIGATE

Affected: 2.4.20-8

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

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

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Downgrade not recommended

This is a core system component: downgrading can break the OS. Apply the distro update or the vendor mitigation.

redhat kernel doc DOWNGRADE

Affected: 2.4.20-8

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.4.20-8

1. Check installed version

apt-cache policy kernel-doc || rpm -q kernel-doc || kernel-doc --version

2. No fixed release: DOWNGRADE to a release before 2.4.20-8 (Debian / Ubuntu)

apt-cache madison kernel-doc sudo apt install kernel-doc=<VERSION_BEFORE_2.4.20-8> sudo apt-mark hold kernel-doc

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

dnf --showduplicates list kernel-doc sudo dnf downgrade kernel-doc-<VERSION_BEFORE_2.4.20-8> sudo dnf versionlock add kernel-doc

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.

redhat kernel source DOWNGRADE

Affected: 2.4.20-8

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.4.20-8

1. Check installed version

apt-cache policy kernel-source || rpm -q kernel-source || kernel-source --version

2. No fixed release: DOWNGRADE to a release before 2.4.20-8 (Debian / Ubuntu)

apt-cache madison kernel-source sudo apt install kernel-source=<VERSION_BEFORE_2.4.20-8> sudo apt-mark hold kernel-source

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

dnf --showduplicates list kernel-source sudo dnf downgrade kernel-source-<VERSION_BEFORE_2.4.20-8> sudo dnf versionlock add kernel-source

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.

linux linux kernel MITIGATE

Affected: 2.2.0 · 2.2.1 · 2.2.2 · 2.2.3 · 2.2.4 · 2.2.5 · 2.2.6 · 2.2.7

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.

Downgrade not recommended

This is a core system component: downgrading can break the OS. Apply the distro update or the vendor mitigation.

netwosix netwosix linux MITIGATE

Affected: 1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0

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: Linux Kernel 2.2.25/2.4.24/2.6.2 - 'mremap()' Local Privilege Escalation
Exploit-DB: Linux Kernel 2.2.25/2.4.24/2.6.2 - 'mremap()' Validator

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-2004-0077?

bigmem kernel: downgrade or apply the listed mitigation; kernel: mitigate or apply the listed mitigation; kernel doc: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2004-0077 being exploited?

CVE-2004-0077 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-2004-0077 affect?

CVE-2004-0077 affects bigmem kernel, kernel, kernel doc. Severity is high (CVSS 7.2). The do_mremap function for the mremap system call in Linux 2.2 to 2.2.25, 2.4 to 2.4.24, and 2.6 to 2.6.2, does not properly check the return value from the do_munmap function when the maximum number of VMA descriptors is exceeded, which al

How urgent is CVE-2004-0077?

Priority 56/100. High severity; Public exploit reference; On your watchlist

Software pages

Linux kernel vulnerabilities

References

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