Ubuntu.comUB:CVE-2021-38507CVE-2021-38507
6.5 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
4.3 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:N/I:P/A:N
0.002 Low
EPSS
Percentile
59.4%
The Opportunistic Encryption feature of HTTP2 (RFC 8164) allows a
connection to be transparently upgraded to TLS while retaining the visual
properties of an HTTP connection, including being same-origin with
unencrypted connections on port 80. However, if a second encrypted port on
the same IP address (e.g. port 8443) did not opt-in to opportunistic
encryption; a network attacker could forward a connection from the browser
to port 443 to port 8443, causing the browser to treat the content of port
8443 as same-origin with HTTP. This was resolved by disabling the
Opportunistic Encryption feature, which had low usage. This vulnerability
affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.
Notes
| Author | Note |
|---|---|
| tyhicks | mozjs contains a copy of the SpiderMonkey JavaScript engine |
| OS | Version | Architecture | Package | Version | Filename |
|---|---|---|---|---|---|
| ubuntu | 18.04 | noarch | firefox | < 94.0+build3-0ubuntu0.18.04.1 | UNKNOWN |
| ubuntu | 20.04 | noarch | firefox | < 94.0+build3-0ubuntu0.20.04.1 | UNKNOWN |
| ubuntu | 21.04 | noarch | firefox | < 94.0+build3-0ubuntu0.21.04.1 | UNKNOWN |
| ubuntu | 21.10 | noarch | firefox | < 94.0+build3-0ubuntu0.21.10.1 | UNKNOWN |
| ubuntu | 22.04 | noarch | firefox | < 94.0+build3-0ubuntu1 | UNKNOWN |
| ubuntu | 22.10 | noarch | firefox | < 94.0+build3-0ubuntu1 | UNKNOWN |
| ubuntu | 23.04 | noarch | firefox | < 94.0+build3-0ubuntu1 | UNKNOWN |
| ubuntu | 23.10 | noarch | firefox | < 94.0+build3-0ubuntu1 | UNKNOWN |
| ubuntu | 24.04 | noarch | firefox | < 94.0+build3-0ubuntu1 | UNKNOWN |
| ubuntu | 18.04 | noarch | mozjs38 | < any | UNKNOWN |
References
launchpad.net/bugs/cve/CVE-2021-38507
nvd.nist.gov/vuln/detail/CVE-2021-38507
security-tracker.debian.org/tracker/CVE-2021-38507
ubuntu.com/security/notices/USN-5131-1
ubuntu.com/security/notices/USN-5152-1
ubuntu.com/security/notices/USN-5248-1
www.cve.org/CVERecord?id=CVE-2021-38507
www.mozilla.org/en-US/security/advisories/mfsa2021-48/#CVE-2021-38507
www.mozilla.org/en-US/security/advisories/mfsa2021-49/#CVE-2021-38507
Related
6.5 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
4.3 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:N/C:N/I:P/A:N
0.002 Low
EPSS
Percentile
59.4%