CVE-2008-2108: The GENERATE_SEED macro in PHP 4.x before 4.4.8 and 5.x before 5.2.5, when running on 64-bit systems, performs

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CRITICAL 9.8REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2008-2108 is a critical-severity flaw (CVSS 9.8) affecting php, fedora, ubuntu linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The GENERATE_SEED macro in PHP 4.x before 4.4.8 and 5.x before 5.2.5, when running on 64-bit systems, performs a multiplication that generates a portion of zero bits during conversion due to insufficient precision, which produces 24 bits of entropy and simplifies brute force attacks against protection mechanisms that use the rand and mt_rand functions.

Why this priority

Critical severity
EPSS top 9%: very likely to be exploited
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	4.3% (top 9%)
CISA exploited list	No
Weakness	CWE-331
Published	2008-05-07
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: canonical · debian · fedoraproject · php

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

Am I affected?

Timeline

2008-05-07 21:20 UTCPublished CVE record published
2026-06-16 22:53 UTCUpdated Record last modified

php php UPGRADE

Affected: >= 4.0.0 and < 4.4.8 · >= 5.0.0 and < 5.2.5

Fixed in: 4.4.8, 5.2.5

Safe to downgrade to: a release before 4.0.0

1. Check installed version

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

2. UPGRADE to 4.4.8 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade php

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade php

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 4.0.0 (Debian / Ubuntu)

apt-cache madison php sudo apt install php=<VERSION_BEFORE_4.0.0> sudo apt-mark hold php

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

dnf --showduplicates list php sudo dnf downgrade php-<VERSION_BEFORE_4.0.0> sudo dnf versionlock add php

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.

fedoraproject fedora MITIGATE

Affected: 8 · 9

Fixed in: no fixed release known

Safe to downgrade to: a release before 8

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.

canonical ubuntu linux MITIGATE

Affected: 6.06 · 7.04 · 7.10 · 8.04

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.06

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.

debian debian linux MITIGATE

Affected: 4.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.0

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.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · rust-tokio · FIXED · 1.54.1-1.fc46 · FEDORA-2026-e7fd815169 · source

sudo dnf upgrade --advisory=FEDORA-2026-e7fd815169

Fedora ELN · libopenraw · FIXED · 0.3.7-2.eln159 · FEDORA-2026-3fa115dd38 · source

sudo dnf upgrade --advisory=FEDORA-2026-3fa115dd38

RHEL 2.1 · php · FIXED · php-4.1.2-2.20

sudo dnf upgrade --advisory=RHSA-2008:0546 rpm -q php

RHEL 3 · php · FIXED · php-4.3.2-48.ent

sudo dnf upgrade --advisory=RHSA-2008:0544 rpm -q php

RHEL 4 · php · FIXED · php-4.3.9-3.22.12

sudo dnf upgrade --advisory=RHSA-2008:0545 rpm -q php

RHEL 5 · php · FIXED · php-5.1.6-20.el5_2.1

sudo dnf upgrade --advisory=RHSA-2008:0544 rpm -q php

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-2008-2108?

php: upgrade to 4.4.8, 5.2.5; fedora: mitigate or apply the listed mitigation; ubuntu linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2008-2108 being exploited?

CVE-2008-2108 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-2008-2108 affect?

CVE-2008-2108 affects php, fedora, ubuntu linux. Severity is critical (CVSS 9.8). The GENERATE_SEED macro in PHP 4.x before 4.4.8 and 5.x before 5.2.5, when running on 64-bit systems, performs a multiplication that generates a portion of zero bits during conversion due to insufficient precision, which produces 24 bits of

How urgent is CVE-2008-2108?

Priority 72/100. Critical severity; EPSS top 9%: very likely to be exploited; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

PHP vulnerabilities · Ubuntu vulnerabilities · Debian vulnerabilities

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References

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