CVE-2020-15670: mozilla firefox Race Condition
Vulnerability summary
CVE-2020-15670 is a high (CVSS 8.8) Race Condition vulnerability in mozilla firefox. EPSS estimates a 1.07% chance of exploitation in the next 30 days, higher than 64.2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 9 · Related 9Timeline
- 01-10-2020PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
Mozilla developers reported memory safety bugs present in Firefox for Android 79. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 80, Firefox ESR < 78.2, Thunderbird < 78.2, and Firefox for Android < 80.
CVSS metrics
3 scores · 2 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS trend
Probability
1.07%
Chance of exploitation in the next 30 days
Percentile
64%
Versus all other CVEs
30-day change
+0.01 pp
From 1.06% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
- CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
- CWE-617Reachable AssertionThe product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
Affected systems
Mozilla5 products
- firefox≥ unspecified, < 80 | < 80.0
- firefox_esr≥ unspecified, < 78.2 | < 78.2
- firefox for android≥ unspecified, < 80
- firefox_mobile< 80.0
- thunderbird≥ unspecified, < 78.2 | < 78.2
Ubuntu5 products
- firefox< 80.0+build2-0ubuntu0.16.04.1 | < 80.0+build2-0ubuntu0.18.04.1 | < 80.0+build2-0ubuntu0.20.04.1
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
- thunderbird< 1:78.8.1+build1-0ubuntu0.18.04.1 | < 1:78.7.1+build1-0ubuntu0.20.04.1
2 vendors · 10 products
References
10 links- bugzilla.mozilla.org/buglist.cgi?bug_id=1651001%2C1653626%2C1656957X Refsource MISCBroken LinkIssue TrackingVendor Advisory