Vulnerability · Published Mar 31, 2021 · Assigned by mozilla
CVE-2021-23984
Medium 6.5
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 1.1% (higher than 66% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)6.5Medium
Exploit odds (30 days)1.1%top 33.8% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
A malicious extension could have opened a popup window lacking an address bar. The title of the popup lacking an address bar should not be fully controllable, but in this situation was. This could have been used to spoof a website and attempt to trick the user into providing credentials. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | firefox | 87.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.21 | firefox | 87.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.22 | firefox | 87.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.23 | firefox | 87.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.20 | firefox-esr | 78.9.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.21 | firefox-esr | 78.9.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.22 | firefox-esr | 78.9.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.23 | firefox-esr | 78.9.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.21 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.22 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.23 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.24 | librewolf | 87.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.20 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.21 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.22 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23984 |
| Alpine:v3.23 | thunderbird | 78.9.0-r0 | ALPINE-CVE-2021-23984 |
| Debian:12 | firefox-esr | 78.9.0esr-1 | DEBIAN-CVE-2021-23984 |
| Debian:13 | firefox-esr | 78.9.0esr-1 | DEBIAN-CVE-2021-23984 |
| Debian:14 | firefox-esr | 78.9.0esr-1 | DEBIAN-CVE-2021-23984 |
| Debian:12 | thunderbird | 1:78.9.0-1 | DEBIAN-CVE-2021-23984 |
| Debian:13 | thunderbird | 1:78.9.0-1 | DEBIAN-CVE-2021-23984 |
| Debian:14 | thunderbird | 1:78.9.0-1 | DEBIAN-CVE-2021-23984 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2021-23984 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox ESR | unspecified – before 78.9 |
| Mozilla | Firefox | unspecified – before 87 |
| Mozilla | Thunderbird | unspecified – before 78.9 |
References
- https://www.mozilla.org/security/advisories/mfsa2021-10/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-12/ x_refsource_MISC
- https://www.mozilla.org/security/advisories/mfsa2021-11/ x_refsource_MISC
- https://bugzilla.mozilla.org/show_bug.cgi?id=1693664 x_refsource_MISC