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Fencer Vulns
critical 9.3

CVE-2009-3376 json

Mozilla Firefox before 3.0.15 and 3.5.x before 3.5.4, and SeaMonkey before 2.0, does not properly handle a right-to-left override (aka RLO…

published 2009-10-29 17 y ago modified 2026-06-16 4 mo ago also EUVD-2009-3358

cvss
9.3
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.2%
EPSS 3.2% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

Summary

Mozilla Firefox before 3.0.15 and 3.5.x before 3.5.4, and SeaMonkey before 2.0, does not properly handle a right-to-left override (aka RLO or U+202E) Unicode character in a download filename, which allows remote attackers to spoof file extensions via a crafted filename, as demonstrated by displaying a non-executable extension for an executable file.

Patch / fix

  • thunderbird RHEL 4 1.5.0.12-25.el4
  • thunderbird RHEL 5 PRODUCTIVITY, RHEL 5 2.0.0.24-2.el5_4
  • seamonkey RHEL 3 1.0.9-0.47.el3
  • seamonkey RHEL 4 1.0.9-50.el4_8
  • seamonkey-nss RHEL 3 1.0.9-0.47.el3
  • seamonkey-chat RHEL 3 1.0.9-0.47.el3
  • seamonkey-chat RHEL 4 1.0.9-50.el4_8
  • seamonkey-mail RHEL 3 1.0.9-0.47.el3

red hat advisories RHSA-2010:0154RHSA-2010:0153RHSA-2009:1531RHSA-2009:1530

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 50.1.0-1.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10071-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2009-3376 updated cvss 2.6

Firefox download filename spoofing with RTL override

  • Red Hat Desktop version 3 seamonkey 1.0.9-0.47.el3, seamonkey-nss 1.0.9-0.47.el3, seamonkey-chat 1.0.9-0.47.el3, seamonkey-mail 1.0.9-0.47.el3, seamonkey-nspr 1.0.9-0.47.el3, seamonkey-js-debugger 1.0.9-0.47.el3, +1 more
    fixed: vendor fix RHSA-2009:1531
  • Red Hat Enterprise Linux (v. 5 server) nspr 4.7.6-1.el5_4, firefox 3.0.15-3.el5_4, xulrunner 1.9.0.15-3.el5_4, xulrunner-devel-unstable 1.9.0.15-3.el5_4
    fixed: vendor fix RHSA-2009:1530
  • Red Hat Enterprise Linux AS version 3 seamonkey 1.0.9-0.47.el3, seamonkey-nss 1.0.9-0.47.el3, seamonkey-chat 1.0.9-0.47.el3, seamonkey-mail 1.0.9-0.47.el3, seamonkey-nspr 1.0.9-0.47.el3, seamonkey-js-debugger 1.0.9-0.47.el3, +1 more Red Hat Enterprise Linux AS version 4 nspr 4.7.6-1.el4_8, firefox 3.0.15-3.el4, seamonkey 1.0.9-50.el4_8, thunderbird 1.5.0.12-25.el4, seamonkey-chat 1.0.9-50.el4_8, seamonkey-mail 1.0.9-50.el4_8, +2 more
    fixed: vendor fix RHSA-2009:1531
  • Red Hat Enterprise Linux Desktop (v. 5 client) nspr 4.7.6-1.el5_4, firefox 3.0.15-3.el5_4, xulrunner 1.9.0.15-3.el5_4, thunderbird 2.0.0.24-2.el5_4, xulrunner-devel-unstable 1.9.0.15-3.el5_4
    fixed: vendor fix RHSA-2009:1530
  • Red Hat Enterprise Linux Desktop version 4 nspr 4.7.6-1.el4_8, firefox 3.0.15-3.el4, seamonkey 1.0.9-50.el4_8, thunderbird 1.5.0.12-25.el4, seamonkey-chat 1.0.9-50.el4_8, seamonkey-mail 1.0.9-50.el4_8, +2 more
    fixed: vendor fix RHSA-2009:1531
  • Red Hat Enterprise Linux Desktop Workstation (v. 5 client) nspr 4.7.6-1.el5_4, xulrunner 1.9.0.15-3.el5_4, xulrunner-devel-unstable 1.9.0.15-3.el5_4
    fixed: vendor fix RHSA-2009:1530
  • Red Hat Enterprise Linux ES version 3 seamonkey 1.0.9-0.47.el3, seamonkey-nss 1.0.9-0.47.el3, seamonkey-chat 1.0.9-0.47.el3, seamonkey-mail 1.0.9-0.47.el3, seamonkey-nspr 1.0.9-0.47.el3, seamonkey-js-debugger 1.0.9-0.47.el3, +1 more Red Hat Enterprise Linux ES version 4 nspr 4.7.6-1.el4_8, firefox 3.0.15-3.el4, seamonkey 1.0.9-50.el4_8, thunderbird 1.5.0.12-25.el4, seamonkey-chat 1.0.9-50.el4_8, seamonkey-mail 1.0.9-50.el4_8, +2 more
    fixed: vendor fix RHSA-2009:1531
  • Red Hat Enterprise Linux Optional Productivity Applications (v. 5 server) thunderbird 2.0.0.24-2.el5_4
    fixed: vendor fix RHSA-2010:0153
show 1 more
  • Red Hat Enterprise Linux WS version 3 seamonkey 1.0.9-0.47.el3, seamonkey-nss 1.0.9-0.47.el3, seamonkey-chat 1.0.9-0.47.el3, seamonkey-mail 1.0.9-0.47.el3, seamonkey-nspr 1.0.9-0.47.el3, seamonkey-js-debugger 1.0.9-0.47.el3, +1 more Red Hat Enterprise Linux WS version 4 nspr 4.7.6-1.el4_8, firefox 3.0.15-3.el4, seamonkey 1.0.9-50.el4_8, thunderbird 1.5.0.12-25.el4, seamonkey-chat 1.0.9-50.el4_8, seamonkey-mail 1.0.9-50.el4_8, +2 more
    fixed: vendor fix RHSA-2009:1531

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

3.18% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 9.3 AV:N/AC:M/Au:N/C:C/I:C/A:C

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.