CVE-2009-0689: Array index error in the (1) dtoa implementation in dtoa.c (aka pdtoa.c) and the (2) gdtoa (aka new dtoa) impl

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MEDIUM 6.8DOWNGRADEDOWNGRADEDOWNGRADE

CVE-2009-0689 is a medium-severity flaw (CVSS 6.8) affecting k-meleon, firefox, seamonkey. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Array index error in the (1) dtoa implementation in dtoa.c (aka pdtoa.c) and the (2) gdtoa (aka new dtoa) implementation in gdtoa/misc.c in libc, as used in multiple operating systems and products including in FreeBSD 6.4 and 7.2, NetBSD 5.0, OpenBSD 4.5, Mozilla Firefox 3.0.x before 3.0.15 and 3.5.x before 3.5.4, K-Meleon 1.5.3, SeaMonkey 1.1.8, and other products, allows context-dependent attackers to cause a denial of service (application cras

Why this priority

EPSS top 2%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	6.8 (Medium)
EPSS exploit chance	29.4% (top 2%)
CISA exploited list	No
Weakness	CWE-119
Published	2009-07-01
Last modified	2026-06-16

Publisher (CNA): CERT/CC · Vendor: freebsd · k-meleon project · mozilla · netbsd · openbsd

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

Am I affected?

Timeline

2009-07-01 13:00 UTCPublished CVE record published
2026-06-16 23:05 UTCUpdated Record last modified

k-meleon project k-meleon DOWNGRADE

Affected: 1.5.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.5.3

1. Check installed version

apt-cache policy k-meleon || rpm -q k-meleon || k-meleon --version

2. No fixed release: DOWNGRADE to a release before 1.5.3 (Debian / Ubuntu)

apt-cache madison k-meleon sudo apt install k-meleon=<VERSION_BEFORE_1.5.3> sudo apt-mark hold k-meleon

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

dnf --showduplicates list k-meleon sudo dnf downgrade k-meleon-<VERSION_BEFORE_1.5.3> sudo dnf versionlock add k-meleon

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.

mozilla firefox DOWNGRADE

Affected: 3.0.1 · 3.0.2 · 3.0.3 · 3.0.4 · 3.0.5 · 3.0.6 · 3.0.7 · 3.0.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0.1

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 3.0.1 (Debian / Ubuntu)

apt-cache madison firefox sudo apt install firefox=<VERSION_BEFORE_3.0.1> sudo apt-mark hold firefox

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

dnf --showduplicates list firefox sudo dnf downgrade firefox-<VERSION_BEFORE_3.0.1> sudo dnf versionlock add firefox

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.

mozilla seamonkey DOWNGRADE

Affected: 1.1.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.1.8

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.1.8 (Debian / Ubuntu)

apt-cache madison seamonkey sudo apt install seamonkey=<VERSION_BEFORE_1.1.8> sudo apt-mark hold seamonkey

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

dnf --showduplicates list seamonkey sudo dnf downgrade seamonkey-<VERSION_BEFORE_1.1.8> sudo dnf versionlock add seamonkey

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.

freebsd freebsd MITIGATE

Affected: 6.4 · 6.4 release · 6.4 release_p2 · 6.4 release_p3 · 6.4 release_p4 · 6.4 release_p5 · 6.4 stable · 7.2

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.4

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.

netbsd netbsd MITIGATE

Affected: 5.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.0

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.

openbsd openbsd MITIGATE

Affected: 4.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.5

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: K-Meleon 1.5.3 - Remote Array Overrun
Exploit-DB: Opera 10.01 - Remote Array Overrun
Exploit-DB: SeaMonkey 1.1.8 - Remote Array Overrun
Exploit-DB: KDE KDELibs 4.3.3 - Remote Array Overrun
Exploit-DB: MATLAB R2009b - 'dtoa' Implementation Memory Corruption
Exploit-DB: Mozilla Firefox 3.5.3 - Floating Point Conversion Heap Overflow
Exploit-DB: KDE 4.3.3 - KDELibs 'dtoa()' Remote Code Execution
Exploit-DB: BSD (Multiple Distributions) - 'gdtoa/misc.c' Memory Corruption

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-2009-0689?

k-meleon: downgrade or apply the listed mitigation; firefox: downgrade or apply the listed mitigation; seamonkey: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2009-0689 being exploited?

CVE-2009-0689 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-2009-0689 affect?

CVE-2009-0689 affects k-meleon, firefox, seamonkey. Severity is medium (CVSS 6.8). Array index error in the (1) dtoa implementation in dtoa.c (aka pdtoa.c) and the (2) gdtoa (aka new dtoa) implementation in gdtoa/misc.c in libc, as used in multiple operating systems and products including in FreeBSD 6.4 and 7.2, NetBSD 5.

How urgent is CVE-2009-0689?

Priority 53/100. EPSS top 2%: very likely to be exploited; Public exploit reference

Software pages

Mozilla Firefox vulnerabilities

Related CVEs

CVE-2009-3008 MEDIUM 4.3 DOWNGRADE K-Meleon 1.5.3 allows context-dependent attackers to spoof the address bar, via window.open with a relative UR

References

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