CVE-2008-5021

nsFrameManager in Firefox 3.x before 3.0.4, Firefox 2.x before 2.0.0.18, Thunderbird 2.x before 2.0.0.18, and SeaMonkey 1.x before 1.1.13 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code by modifying properties of a file input element while it is still being initialized, then using the blur method to access uninitialized memory.

Published: 2008-11-13 Last update: 2026-04-23 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2008-5021 is rated High Risk (69.3/100): CVSS Critical severity, with high exploitation likelihood (EPSS 23.76%, 96th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2008-5021

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-09 25.26% 23.76% -1.50%
2 2025-07-29 16.20% 25.26% +9.06%
3 2025-06-01 — 16.20% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2008-5021

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.3 2.0 HIGH
AV:N/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.6 10.0 [email protected]

Weakness enumeration for CVE-2008-5021

OS Trackers for CVE-2008-5021

vendor priority summary link
gentoo high CVE-2008-5021: 1 GLSA(s) (201301-01), 14 atom(s) (dev-libs/nss, mail-client/mozilla-thunderbird, …); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2008-5021
redhat critical — https://access.redhat.com/security/cve/CVE-2008-5021
ubuntu medium CVE-2008-5021 medium priority: Ubuntu including 10 source packages (firefox, firefox-3.0, …), 50 status rows across 5 suites (dapper, gutsy, hardy, intrepid, upstream): DNE 21, released 21, needs-triage 5, ignored 3. https://ubuntu.com/security/CVE-2008-5021

Affected software / configurations for CVE-2008-5021

Vendor Product Version Raw CPE
mozilla firefox >= 2.0, < 2.0.0.18 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla firefox >= 3.0, < 3.0.4 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla seamonkey >= 1.0, < 1.1.13 cpe:2.3:a:mozilla:seamonkey:*:*:*:*:*:*:*:*
mozilla thunderbird >= 2.0, < 2.0.0.18 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
debian debian_linux 4.0 cpe:2.3:o:debian:debian_linux:4.0:*:*:*:*:*:*:*
canonical ubuntu_linux 6.06 cpe:2.3:o:canonical:ubuntu_linux:6.06:*:*:*:lts:*:*:*
canonical ubuntu_linux 7.10 cpe:2.3:o:canonical:ubuntu_linux:7.10:*:*:*:*:*:*:*
canonical ubuntu_linux 8.04 cpe:2.3:o:canonical:ubuntu_linux:8.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 8.10 cpe:2.3:o:canonical:ubuntu_linux:8.10:*:*:*:*:*:*:*
fedoraproject fedora 8 cpe:2.3:o:fedoraproject:fedora:8:*:*:*:*:*:*:*
fedoraproject fedora 9 cpe:2.3:o:fedoraproject:fedora:9:*:*:*:*:*:*:*
suse linux_enterprise_debuginfo 10 cpe:2.3:a:suse:linux_enterprise_debuginfo:10:sp2:*:*:*:*:*:*
novell linux_desktop 9 cpe:2.3:o:novell:linux_desktop:9:*:*:*:*:*:*:*
novell open_enterprise_server — cpe:2.3:o:novell:open_enterprise_server:-:*:*:*:*:*:*:*
opensuse opensuse 10.2 cpe:2.3:o:opensuse:opensuse:10.2:*:*:*:*:*:*:*
opensuse opensuse 10.3 cpe:2.3:o:opensuse:opensuse:10.3:*:*:*:*:*:*:*
opensuse opensuse 11.0 cpe:2.3:o:opensuse:opensuse:11.0:*:*:*:*:*:*:*
suse linux_enterprise_desktop 10 cpe:2.3:o:suse:linux_enterprise_desktop:10:-:*:*:*:*:*:*
suse linux_enterprise_server 9 cpe:2.3:o:suse:linux_enterprise_server:9:*:*:*:*:*:*:*
suse linux_enterprise_server 10 cpe:2.3:o:suse:linux_enterprise_server:10:sp1:*:*:*:*:*:*
suse linux_enterprise_software_development_kit 10 cpe:2.3:o:suse:linux_enterprise_software_development_kit:10:sp1:*:*:*:*:*:*
suse linux_enterprise_software_development_kit 10 cpe:2.3:o:suse:linux_enterprise_software_development_kit:10:sp2:*:*:*:*:*:*

References for CVE-2008-5021

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2008-11/msg00004.html Mailing List Third Party Advisory
http://secunia.com/advisories/32684 Broken Link Third Party Advisory
http://secunia.com/advisories/32693 Broken Link Third Party Advisory
http://secunia.com/advisories/32694 Broken Link Third Party Advisory
http://secunia.com/advisories/32695 Broken Link Third Party Advisory
http://secunia.com/advisories/32713 Broken Link Third Party Advisory
http://secunia.com/advisories/32714 Broken Link Third Party Advisory
http://secunia.com/advisories/32715 Broken Link Third Party Advisory
http://secunia.com/advisories/32721 Broken Link Third Party Advisory
http://secunia.com/advisories/32778 Broken Link Third Party Advisory
http://secunia.com/advisories/32798 Broken Link Third Party Advisory
http://secunia.com/advisories/32845 Broken Link Third Party Advisory
http://secunia.com/advisories/32853 Broken Link Third Party Advisory
http://secunia.com/advisories/33433 Broken Link Third Party Advisory
http://secunia.com/advisories/33434 Broken Link Third Party Advisory
http://secunia.com/advisories/34501 Broken Link Third Party Advisory
http://sunsolve.sun.com/search/document.do?assetkey=1-26-256408-1 Broken Link
http://ubuntu.com/usn/usn-667-1 Third Party Advisory
http://www.debian.org/security/2008/dsa-1669 Mailing List Third Party Advisory
http://www.debian.org/security/2008/dsa-1671 Mailing List Third Party Advisory
http://www.debian.org/security/2009/dsa-1696 Mailing List Third Party Advisory
http://www.debian.org/security/2009/dsa-1697 Mailing List Third Party Advisory
http://www.mandriva.com/security/advisories?name=MDVSA-2008:228 Broken Link Third Party Advisory
http://www.mandriva.com/security/advisories?name=MDVSA-2008:230 Broken Link Third Party Advisory
http://www.mandriva.com/security/advisories?name=MDVSA-2008:235 Broken Link Third Party Advisory
http://www.mozilla.org/security/announce/2008/mfsa2008-55.html Vendor Advisory
http://www.redhat.com/support/errata/RHSA-2008-0976.html Broken Link Third Party Advisory
http://www.redhat.com/support/errata/RHSA-2008-0977.html Broken Link Third Party Advisory
http://www.redhat.com/support/errata/RHSA-2008-0978.html Broken Link Third Party Advisory
http://www.securityfocus.com/bid/32281 Broken Link Third Party Advisory VDB Entry
http://www.securitytracker.com/id?1021186 Broken Link Third Party Advisory VDB Entry
http://www.us-cert.gov/cas/techalerts/TA08-319A.html Third Party Advisory US Government Resource
http://www.vupen.com/english/advisories/2008/3146 Broken Link Third Party Advisory
http://www.vupen.com/english/advisories/2009/0977 Broken Link Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=460002 Issue Tracking Vendor Advisory
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9642 Broken Link Third Party Advisory
https://www.redhat.com/archives/fedora-package-announce/2008-November/msg00366.html Mailing List Third Party Advisory
https://www.redhat.com/archives/fedora-package-announce/2008-November/msg00385.html Mailing List Third Party Advisory
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