Skip to content
Noroxi
CVE-2009-5017· NVD / CVE Program· CNA mitre

Mozilla Firefox before 3.6 Beta 3 does not properly handle overlong UTF-8 encoding, which makes it easier for remote attackers to bypass cro

Mozilla Firefox before 3.6 Beta 3 does not properly handle overlong UTF-8 encoding, which makes it easier for remote attackers to bypass cross-site scripting (XSS) protection mechanisms via a crafted string, a different vulnerability than CVE-2010-1210.

MediumCVSS 4.3 · v2.0—No exploit Fix available
Published
Nov 12, 2010
Updated
Jun 16, 2026
EPSS
1.8% · 78th percentile
Follow this CVE

Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
17 / 40 · 4.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 1.8%

Affected systems

VendorProduct
mozillafirefox

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • mozilla firefoxup to 3.6 inclusive
  • mozilla firefox3.6

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Red Hat:enterprise_linux:4::asfirefoxbefore 0:3.6.4-8.el40:3.6.4-8.el4
Red Hat:enterprise_linux:4::asfirefox-debuginfobefore 0:3.6.4-8.el40:3.6.4-8.el4
Red Hat:enterprise_linux:5::clientescbefore 0:1.1.0-12.el50:1.1.0-12.el5
Red Hat:enterprise_linux:5::clientesc-debuginfobefore 0:1.1.0-12.el50:1.1.0-12.el5
Red Hat:enterprise_linux:5::clientfirefoxbefore 0:3.6.4-8.el50:3.6.4-8.el5
Red Hat:enterprise_linux:5::clientfirefox-debuginfobefore 0:3.6.4-8.el50:3.6.4-8.el5
Red Hat:enterprise_linux:5::clientgnome-python2-extrasbefore 0:2.14.2-7.el50:2.14.2-7.el5
Red Hat:enterprise_linux:5::clientgnome-python2-extras-debuginfobefore 0:2.14.2-7.el50:2.14.2-7.el5
Red Hat:enterprise_linux:5::clientgnome-python2-gtkhtml2before 0:2.14.2-7.el50:2.14.2-7.el5
Red Hat:enterprise_linux:5::clientgnome-python2-gtkmozembedbefore 0:2.14.2-7.el50:2.14.2-7.el5
Red Hat:enterprise_linux:5::clientgnome-python2-gtkspellbefore 0:2.14.2-7.el50:2.14.2-7.el5
Red Hat:enterprise_linux:5::clientgnome-python2-libeggbefore 0:2.14.2-7.el50:2.14.2-7.el5
Red Hat:enterprise_linux:5::clienttotem-mozpluginbefore 0:2.16.7-7.el50:2.16.7-7.el5
Red Hat:enterprise_linux:5::clientyelpbefore 0:2.16.0-26.el50:2.16.0-26.el5
Red Hat:enterprise_linux:5::clientyelp-debuginfobefore 0:2.16.0-26.el50:2.16.0-26.el5
Red Hat:enterprise_linux:5::client_workstationdevhelpbefore 0:0.12-21.el50:0.12-21.el5
Red Hat:enterprise_linux:5::client_workstationdevhelp-debuginfobefore 0:0.12-21.el50:0.12-21.el5
Red Hat:enterprise_linux:5::client_workstationdevhelp-develbefore 0:0.12-21.el50:0.12-21.el5
Red Hat:enterprise_linux:5::client_workstationtotembefore 0:2.16.7-7.el50:2.16.7-7.el5
Red Hat:enterprise_linux:5::client_workstationtotem-debuginfobefore 0:2.16.7-7.el50:2.16.7-7.el5
Red Hat:enterprise_linux:5::client_workstationtotem-develbefore 0:2.16.7-7.el50:2.16.7-7.el5
Red Hat:enterprise_linux:5::client_workstationxulrunnerbefore 0:1.9.2.4-10.el50:1.9.2.4-10.el5
Red Hat:enterprise_linux:5::client_workstationxulrunner-debuginfobefore 0:1.9.2.4-10.el50:1.9.2.4-10.el5
Red Hat:enterprise_linux:5::client_workstationxulrunner-develbefore 0:1.9.2.4-10.el50:1.9.2.4-10.el5

Same product

mozilla: all records

Other highest-scoring records for the same primary product.

  • CVE-2010-3765Mozilla Firefox 3.5.x through 3.5.14 and 3.6.x through 3.6.11, Thunderbird 3.1.6 before 3.1.6 and 3.0.x before 3.0.10, and SeaMonkey 2.x befKEV
    94Now
  • CVE-2019-11708Insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes can result in the non-sandboxeKEV
    87Now
  • CVE-2015-4495The PDF reader in Mozilla Firefox before 39.0.3, Firefox ESR 38.x before 38.1.1, and Firefox OS before 2.2 allows remote attackers to bypassKEV
    86Now
  • CVE-2013-1690Mozilla Firefox before 22.0, Firefox ESR 17.x before 17.0.7, Thunderbird before 17.0.7, and Thunderbird ESR 17.x before 17.0.7 do not properKEV
    86Now
  • CVE-2019-17026Incorrect alias information in IonMonkey JIT compiler for setting array elements could lead to a type confusion.KEV
    79This week
  • CVE-2024-9680An attacker was able to achieve code execution in the content process by exploiting a use-after-free in Animation timelines.KEV
    76This week

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
red hat:devhelp0:0.12-21.el5 · Red Hat:enterprise_linux:5::client_workstationPackage registry (OSV)
red hat:devhelp-debuginfo0:0.12-21.el5 · Red Hat:enterprise_linux:5::client_workstationPackage registry (OSV)
red hat:devhelp-devel0:0.12-21.el5 · Red Hat:enterprise_linux:5::client_workstationPackage registry (OSV)
red hat:esc0:1.1.0-12.el5 · Red Hat:enterprise_linux:5::clientPackage registry (OSV)
red hat:firefox0:3.6.4-8.el4 · Red Hat:enterprise_linux:4::asPackage registry (OSV)
red hat:firefox-debuginfo0:3.6.4-8.el4 · Red Hat:enterprise_linux:4::asPackage registry (OSV)
red hat:totem0:2.16.7-7.el5 · Red Hat:enterprise_linux:5::client_workstationPackage registry (OSV)
red hat:totem-debuginfo0:2.16.7-7.el5 · Red Hat:enterprise_linux:5::client_workstationPackage registry (OSV)
red hat:totem-devel0:2.16.7-7.el5 · Red Hat:enterprise_linux:5::client_workstationPackage registry (OSV)
red hat:xulrunner0:1.9.2.4-10.el5 · Red Hat:enterprise_linux:5::client_workstationPackage registry (OSV)
red hat:xulrunner-debuginfo0:1.9.2.4-10.el5 · Red Hat:enterprise_linux:5::client_workstationPackage registry (OSV)
red hat:xulrunner-devel0:1.9.2.4-10.el5 · Red Hat:enterprise_linux:5::client_workstationPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

    If successful

    Confidentiality
    none
    Integrity
    P · data or configuration can be modified
    Availability
    none
    Attack complexity
    M
    Confidentiality impact
    None
    Integrity impact
    P
    Availability impact
    None

    Weakness class (CWE)

    CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

    CVSS vector

    AV:N/AC:M/Au:N/C:N/I:P/A:N

    nvd-primary

    Root cause

    User content is inserted into the page as HTML. The browser interprets the content as code rather than data.

    The bug in code

    The whole CWE-79 class

    A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

    Vulnerable

    ts
    commentEl.innerHTML = comment.body;

    Fixed

    ts
    commentEl.textContent = comment.body;

    Attack context

    MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

    ATT&CK techniques

    —

    Noroxi analysis

    No Noroxi analysis for this record yet

    We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

    We use this product, ask for help

    Change log

    1. Fix✗ → ✓

    For records you follow, these changes also arrive as notifications. →

    References

    Vendor advisories and official records. Exploit/PoC links are deliberately left out.

    All records