Vulnerability · Published Dec 9, 2020 · Assigned by mozilla
CVE-2020-26953
Medium 4.3
In plain English
A medium-severity security flaw in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.3% (higher than 70% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)4.3Medium
Exploit odds (30 days)1.3%top 29.6% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
It was possible to cause the browser to enter fullscreen mode without displaying the security UI; thus making it possible to attempt a phishing attack or otherwise confuse the user. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | firefox | 83.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.21 | firefox | 83.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.22 | firefox | 83.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.23 | firefox | 83.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.20 | firefox-esr | 78.5.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.21 | firefox-esr | 78.5.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.22 | firefox-esr | 78.5.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.23 | firefox-esr | 78.5.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.21 | librewolf | 83.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.22 | librewolf | 83.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.23 | librewolf | 83.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.24 | librewolf | 83.0-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.20 | thunderbird | 78.5.1-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.21 | thunderbird | 78.5.1-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.22 | thunderbird | 78.5.1-r0 | ALPINE-CVE-2020-26953 |
| Alpine:v3.23 | thunderbird | 78.5.1-r0 | ALPINE-CVE-2020-26953 |
| Debian:12 | firefox-esr | 78.5.0esr-1 | DEBIAN-CVE-2020-26953 |
| Debian:13 | firefox-esr | 78.5.0esr-1 | DEBIAN-CVE-2020-26953 |
| Debian:14 | firefox-esr | 78.5.0esr-1 | DEBIAN-CVE-2020-26953 |
| Debian:12 | thunderbird | 1:78.5.0-1 | DEBIAN-CVE-2020-26953 |
| Debian:13 | thunderbird | 1:78.5.0-1 | DEBIAN-CVE-2020-26953 |
| Debian:14 | thunderbird | 1:78.5.0-1 | DEBIAN-CVE-2020-26953 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 83 |
| Mozilla | Firefox ESR | < 78.5 |
| Mozilla | Thunderbird | < 78.5 |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1656741 x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2020-50/ x_refsource_CONFIRM
- https://www.mozilla.org/security/advisories/mfsa2020-52/ x_refsource_CONFIRM
- https://www.mozilla.org/security/advisories/mfsa2020-51/ x_refsource_CONFIRM