Description
An out-of-bounds read during the processing of glyph widths during text layout. This results in a potentially exploitable crash and could allow an attacker to read otherwise inaccessible memory. This vulnerability affects Thunderbird < 52.1, Firefox ESR < 45.9, Firefox ESR < 52.1, and Firefox < 53.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 52.1 | 52.1 |
| Mozilla | Firefox ESR | unspecified – < 45.9, unspecified – < 52.1 | 45.9 |
| Mozilla | Firefox | unspecified – < 53 | 53 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | firefox-esr | 45.9.0esr-1 | — |
| Debian 13 | firefox-esr | 45.9.0esr-1 | — |
| Debian 12 | firefox-esr | 45.9.0esr-1 | — |
| Debian 8 | firefox-esr | 45.9.0esr-1~deb8u1 | DSA-3831-1 |
| Debian 7 | firefox-esr | 45.9.0esr-1~deb7u1 | DLA-906-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | firefox | 53.0+build6-0ubuntu0.16.04.1 | USN-3260-1 |
| Ubuntu 16.04 LTS | thunderbird | 1:52.1.1+build1-0ubuntu0.16.04.1 | USN-3278-1 |
| Ubuntu 14.04 LTS | firefox | 53.0+build6-0ubuntu0.14.04.1 | USN-3260-1 |
| Ubuntu 14.04 LTS | thunderbird | 1:52.1.1+build1-0ubuntu0.14.04.1 | USN-3278-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | firefox | 52.1.0-2.el7_3 | RHSA-2017:1106 |
| RHEL 7 | thunderbird | 52.1.0-1.el7_3 | RHSA-2017:1201 |
| RHEL 6 | firefox | 52.1.0-2.el6_9 | RHSA-2017:1104 |
| RHEL 6 | thunderbird | 52.1.0-1.el6_9 | RHSA-2017:1201 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | MozillaFirefox | 45.9.0esr-105.1 | SUSE-SU-2017:1669-1, SUSE-SU-2017:1248-1 |
| SLES 12 SP2 | MozillaFirefox-branding-SLE | 52-31.1 | SUSE-SU-2017:1669-1 |
| SLES 12 SP2 | java-1_8_0-openjdk | 1.8.0.121-23.4 | SUSE-SU-2017:1248-1 |
| SLES 12 SP2 | mozilla-nspr | 4.13.1-18.1 | SUSE-SU-2017:1248-1 |
| SLES 12 SP2 | mozilla-nss | 3.29.5-57.1 | SUSE-SU-2017:1248-1 |
| SLES 12 SP1 | MozillaFirefox | 45.9.0esr-105.1 | SUSE-SU-2017:1669-1, SUSE-SU-2017:1248-1 |
| SLES 12 SP1 | MozillaFirefox-branding-SLE | 52-31.1 | SUSE-SU-2017:1669-1 |
| SLES 12 SP1 | java-1_8_0-openjdk | 1.8.0.121-23.4 | SUSE-SU-2017:1248-1 |
| SLES 12 SP1 | mozilla-nspr | 4.13.1-18.1 | SUSE-SU-2017:1248-1 |
| SLES 12 SP1 | mozilla-nss | 3.29.5-57.1 | SUSE-SU-2017:1248-1 |
| SLES 12 | MozillaFirefox | 45.9.0esr-105.1 | SUSE-SU-2017:1669-1, SUSE-SU-2017:1248-1 |
| SLES 12 | MozillaFirefox-branding-SLE | 52-31.1 | SUSE-SU-2017:1669-1 |
| SLES 12 | mozilla-nspr | 4.13.1-18.1 | SUSE-SU-2017:1248-1 |
| SLES 12 | mozilla-nss | 3.29.5-57.1 | SUSE-SU-2017:1248-1 |
| SLES 11 SP4 | MozillaFirefox | 45.9.0esr-71.2 | SUSE-SU-2017:2235-1, SUSE-SU-2017:1175-1 |
| SLES 11 SP4 | MozillaFirefox-branding-SLED | 52-24.3.44 | SUSE-SU-2017:2235-1 |
| SLES 11 SP4 | firefox-gcc5 +1 | 5.3.1+r233831-7.1 | SUSE-SU-2017:2235-1 |
| SLES 11 SP4 | mozilla-nspr | 4.13.1-32.1 | SUSE-SU-2017:1175-1 |
| SLES 11 SP4 | mozilla-nss | 3.29.5-46.1 | SUSE-SU-2017:2235-1, SUSE-SU-2017:1175-1 |
| SLES 11 SP3 | MozillaFirefox | 45.9.0esr-71.2 | SUSE-SU-2017:2235-1, SUSE-SU-2017:1175-1 |
| SLES 11 SP3 | MozillaFirefox-branding-SLED | 52-24.3.44 | SUSE-SU-2017:2235-1 |
| SLES 11 SP3 | firefox-gcc5 +1 | 5.3.1+r233831-7.1 | SUSE-SU-2017:2235-1 |
| SLES 11 SP3 | mozilla-nspr | 4.13.1-32.1 | SUSE-SU-2017:1175-1 |
| SLES 11 SP3 | mozilla-nss | 3.29.5-46.1 | SUSE-SU-2017:2235-1, SUSE-SU-2017:1175-1 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP2 | MozillaFirefox | 45.9.0esr-105.1 | SUSE-SU-2017:1669-1, SUSE-SU-2017:1248-1 |
| SLES for SAP 12 SP2 | MozillaFirefox-branding-SLE | 52-31.1 | SUSE-SU-2017:1669-1 |
| SLES for SAP 12 SP2 | java-1_8_0-openjdk | 1.8.0.121-23.4 | SUSE-SU-2017:1248-1 |
| SLES for SAP 12 SP2 | mozilla-nspr | 4.13.1-18.1 | SUSE-SU-2017:1248-1 |
| SLES for SAP 12 SP2 | mozilla-nss | 3.29.5-57.1 | SUSE-SU-2017:1248-1 |
| SLES for SAP 12 SP1 | MozillaFirefox | 45.9.0esr-105.1 | SUSE-SU-2017:1669-1, SUSE-SU-2017:1248-1 |
| SLES for SAP 12 SP1 | MozillaFirefox-branding-SLE | 52-31.1 | SUSE-SU-2017:1669-1 |
| SLES for SAP 12 SP1 | java-1_8_0-openjdk | 1.8.0.121-23.4 | SUSE-SU-2017:1248-1 |
| SLES for SAP 12 SP1 | mozilla-nspr | 4.13.1-18.1 | SUSE-SU-2017:1248-1 |
| SLES for SAP 12 SP1 | mozilla-nss | 3.29.5-57.1 | SUSE-SU-2017:1248-1 |
| SLES for SAP 12 | MozillaFirefox | 45.9.0esr-105.1 | SUSE-SU-2017:1669-1, SUSE-SU-2017:1248-1 |
| SLES for SAP 12 | MozillaFirefox-branding-SLE | 52-31.1 | SUSE-SU-2017:1669-1 |
| SLES for SAP 12 | mozilla-nspr | 4.13.1-18.1 | SUSE-SU-2017:1248-1 |
| SLES for SAP 12 | mozilla-nss | 3.29.5-57.1 | SUSE-SU-2017:1248-1 |
| SLES for SAP 11 SP4 | MozillaFirefox | 45.9.0esr-71.2 | SUSE-SU-2017:2235-1, SUSE-SU-2017:1175-1 |
| SLES for SAP 11 SP4 | MozillaFirefox-branding-SLED | 52-24.3.44 | SUSE-SU-2017:2235-1 |
| SLES for SAP 11 SP4 | firefox-gcc5 +1 | 5.3.1+r233831-7.1 | SUSE-SU-2017:2235-1 |
| SLES for SAP 11 SP4 | mozilla-nspr | 4.13.1-32.1 | SUSE-SU-2017:1175-1 |
| SLES for SAP 11 SP4 | mozilla-nss | 3.29.5-46.1 | SUSE-SU-2017:2235-1, SUSE-SU-2017:1175-1 |
| SUSE Package Hub 12 | MozillaThunderbird | 52.1.0-30.1 | openSUSE-SU-2017:1268-1 |
| SUSE OpenStack Cloud 6 | MozillaFirefox | 52.2.0esr-108.3 | SUSE-SU-2017:1669-1 |
| SUSE OpenStack Cloud 6 | MozillaFirefox-branding-SLE | 52-31.1 | SUSE-SU-2017:1669-1 |
| SUSE OpenStack Cloud 5 | MozillaFirefox | 45.9.0esr-71.2 | SUSE-SU-2017:1175-1 |
| SUSE OpenStack Cloud 5 | mozilla-nspr | 4.13.1-32.1 | SUSE-SU-2017:1175-1 |
| SUSE OpenStack Cloud 5 | mozilla-nss | 3.29.5-46.1 | SUSE-SU-2017:1175-1 |
| SUSE Manager Proxy 2.1 | MozillaFirefox | 45.9.0esr-71.2 | SUSE-SU-2017:1175-1 |
| SUSE Manager Proxy 2.1 | mozilla-nspr | 4.13.1-32.1 | SUSE-SU-2017:1175-1 |
| SUSE Manager Proxy 2.1 | mozilla-nss | 3.29.5-46.1 | SUSE-SU-2017:1175-1 |
| SUSE Manager 2.1 | MozillaFirefox | 45.9.0esr-71.2 | SUSE-SU-2017:1175-1 |
| SUSE Manager 2.1 | mozilla-nspr | 4.13.1-32.1 | SUSE-SU-2017:1175-1 |
| SUSE Manager 2.1 | mozilla-nss | 3.29.5-46.1 | SUSE-SU-2017:1175-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | MozillaFirefox | 45.9.0esr-71.2 | SUSE-SU-2017:2235-1, SUSE-SU-2017:1175-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | MozillaFirefox-branding-SLED | 52-24.3.44 | SUSE-SU-2017:2235-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | firefox-gcc5 +1 | 5.3.1+r233831-7.1 | SUSE-SU-2017:2235-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | mozilla-nspr | 4.13.1-32.1 | SUSE-SU-2017:1175-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | mozilla-nss | 3.29.5-46.1 | SUSE-SU-2017:2235-1, SUSE-SU-2017:1175-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 91.1.1-1.1 | openSUSE-SU-2024:10601-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | firefox | 52.1.0-2.0.1.el7_3 | ELSA-2017-1106 |
| Oracle Linux 7 | thunderbird | 52.1.0-1.0.1.el7_3 | ELSA-2017-1201 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- Mozilla Firefox < 53 - 'gfxTextRun' Out-of-Bounds Read EDB-42071 · dos · May 25, 2017 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 17
- USN-3278-1 thunderbird vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- USN-3260-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- RHSA-2017:1201 Red Hat Security Advisory: thunderbird security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2017:1104 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2017:1106 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- DLA-906-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3831-1 firefox-esr - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2017:2235-1 Security update for MozillaFirefox, MozillaFirefox-branding-SLED, firefox-gcc5, mozilla-nss SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:1175-1 Security update for MozillaFirefox, mozilla-nss, mozilla-nspr SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10600-1 MozillaFirefox-92.0-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2017:1268-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:1248-1 Security update for MozillaFirefox, mozilla-nss, mozilla-nspr, java-1_8_0-openjdk SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:1669-1 Security update for MozillaFirefox, MozillaFirefox-branding-SLE SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10601-1 MozillaThunderbird-91.1.1-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ELSA-2017-1201 Important: thunderbird security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · May 8, 2017
- ELSA-2017-1106 Critical: firefox security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Apr 20, 2017
References
- 42071 exploit
- RHSA-2017:1106 vendor-advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1343552
- https://www.mozilla.org/security/advisories/mfsa2017-12/
- https://www.mozilla.org/security/advisories/mfsa2017-11/
- https://www.mozilla.org/security/advisories/mfsa2017-10/
- 97940 vdb-entry
- DSA-3831 vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2017-13/
- 1038320 vdb-entry
- RHSA-2017:1104 vendor-advisory
- RHSA-2017:1201 vendor-advisory