CVE-2020-26950
Mozilla: Write side effects in MCallGetProperty opcode not accounted for
Severity Score
8.8
*CVSS v3.1
Exploit Likelihood
*EPSS
Affected Versions
*CPE
Public Exploits
3
*Multiple Sources
Exploited in Wild
-
*KEV
Decision
-
*SSVC
Descriptions
In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting in an exploitable use-after-free condition. This vulnerability affects Firefox < 82.0.3, Firefox ESR < 78.4.1, and Thunderbird < 78.4.2.
En determinadas circunstancias, el opcode MCallGetProperty puede ser emitido con suposiciones no cumplidas, resultando en una condición de uso de la memoria previamente liberada explotable. Esta vulnerabilidad afecta a Firefox versiones anteriores a 82.0.3, Firefox ESR versiones anteriores a 78.4.1, y Thunderbird versiones anteriores a 78.4.2
A use-after-free was discovered in Firefox. If a user were tricked in to opening a specially crafted website, an attacker could exploit this to execute arbitrary code.
*Credits:
N/A
CVSS Scores
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Attack Vector
Attack Complexity
Authentication
Confidentiality
Integrity
Availability
* Common Vulnerability Scoring System
SSVC
- Decision:-
Exploitation
Automatable
Tech. Impact
* Organization's Worst-case Scenario
Timeline
- 2020-10-12 CVE Reserved
- 2020-11-11 CVE Published
- 2022-03-01 First Exploit
- 2024-08-04 CVE Updated
- 2025-03-30 EPSS Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
CWE
- CWE-416: Use After Free
CAPEC
References (8)
| URL | Tag | Source |
|---|---|---|
| https://www.mozilla.org/en-US/security/advisories/mfsa2020-49/#CVE-2020-26950 | ||
| https://www.sentinelone.com/labs/firefox-jit-use-after-frees-exploiting-cve-2020-26950 |
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|---|---|
| https://www.mozilla.org/security/advisories/mfsa2020-49 | 2022-04-08 | |
| https://access.redhat.com/security/cve/CVE-2020-26950 | 2020-11-23 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1896306 | 2020-11-23 |
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Mozilla Search vendor "Mozilla" | Firefox Search vendor "Mozilla" for product "Firefox" | < 82.0.3 Search vendor "Mozilla" for product "Firefox" and version " < 82.0.3" | - |
Affected
| ||||||
| Mozilla Search vendor "Mozilla" | Firefox Esr Search vendor "Mozilla" for product "Firefox Esr" | < 78.4.1 Search vendor "Mozilla" for product "Firefox Esr" and version " < 78.4.1" | - |
Affected
| ||||||
| Mozilla Search vendor "Mozilla" | Thunderbird Search vendor "Mozilla" for product "Thunderbird" | < 78.4.2 Search vendor "Mozilla" for product "Thunderbird" and version " < 78.4.2" | - |
Affected
| ||||||