Multiple vulnerabilities in Mozilla Thunderbird

1) Security features bypass

EUVDB-ID: #VU57876

Risk: High

CVSSv4.0: 6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-38503

CWE-ID: CWE-254 - Security Features

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to the iframe sandbox rules were not correctly applied to XSLT stylesheets. A remote attacker can load use an iframe to bypass restrictions such as executing scripts or navigating the top-level frame.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 9.0.1 - 91.2.1

CPE2.3

• cpe:2.3:a:mozilla:mozilla_thunderbird:91.2.1:*:*:*:*:*:*:*

External links

https://www.mozilla.org/en-US/security/advisories/mfsa2021-50/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Use-after-free

EUVDB-ID: #VU57878

Risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-38504

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error when interacting with an HTML input element's file picker dialog with webkitdirectory set. A remote attacker can trick the victim to open a specially crafted website, trigger a use-after-free error and execute arbitrary code on the system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 9.0.1 - 91.2.1

CPE2.3

External links

https://www.mozilla.org/en-US/security/advisories/mfsa2021-50/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Information disclosure

EUVDB-ID: #VU57879

Risk: Low

CVSSv4.0: 0.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-38505

CWE-ID: CWE-200 - Information exposure

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to absence of support for a new feature in Windows 10 known as Cloud Clipboard that, if enabled, will record data copied to the clipboard to the cloud, and make it available on other computers in certain scenarios. Applications that wish to prevent copied data from being recorded in Cloud History must use specific clipboard formats, which were not implemented in previous versions of Firefox and Firefox ESR.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 9.0.1 - 91.2.1

CPE2.3

External links

https://www.mozilla.org/en-US/security/advisories/mfsa2021-50/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Insufficient UI Warning of Dangerous Operations

EUVDB-ID: #VU57880

Risk: Medium

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-38506

CWE-ID: CWE-357 - Insufficient UI Warning of Dangerous Operations

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform spoofing attacks.

The vulnerability exists due to Firefox could have entered fullscreen mode without notification or warning to the user. A remote attacker can perform spoofing attacks on the browser UI.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 9.0.1 - 91.2.1

CPE2.3

External links

https://www.mozilla.org/en-US/security/advisories/mfsa2021-50/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Security features bypass

EUVDB-ID: #VU57881

Risk: Low

CVSSv4.0: 0.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-38507

CWE-ID: CWE-254 - Security Features

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists in the Opportunistic Encryption feature of HTTP2, which 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 from port 443 to port 8443, causing the browser to treat the content of port 8443 as same-origin with HTTP. As a result, a remote attacker can bypass Same-Origin-Policy on services hosted on other ports.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 9.0.1 - 91.2.1

CPE2.3

External links

https://www.mozilla.org/en-US/security/advisories/mfsa2021-50/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

6) Improper Restriction of Rendered UI Layers or Frames

EUVDB-ID: #VU57882

Risk: Low

CVSSv4.0: 0.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-38508

CWE-ID: CWE-1021 - Improper Restriction of Rendered UI Layers or Frames

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to Firefox displays the form validity message in the correct location at the same time as a permission prompt (such as for geolocation). The validity message could have obscured the prompt, resulting in the user potentially being tricked into granting the permission.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 9.0.1 - 91.2.1

CPE2.3

External links

https://www.mozilla.org/en-US/security/advisories/mfsa2021-50/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

7) Improper Restriction of Rendered UI Layers or Frames

EUVDB-ID: #VU57883

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-38509

CWE-ID: CWE-1021 - Improper Restriction of Rendered UI Layers or Frames

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to incorrect processing of an unusual sequence of attacker-controlled events. A remote attacker can display a Javascript alert() dialog with arbitrary (although unstyled) contents over top of arbitrary webpage of the attacker's choosing.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 9.0.1 - 91.2.1

CPE2.3

External links

https://www.mozilla.org/en-US/security/advisories/mfsa2021-50/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

8) Insufficient UI Warning of Dangerous Operations

EUVDB-ID: #VU57884

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-38510

CWE-ID: CWE-357 - Insufficient UI Warning of Dangerous Operations

Exploit availability: No

Description

The vulnerability allows a remote attacker to silently download dangerous files on the system.

The vulnerability exists due to the executable file warning is not presented to the user when downloading .inetloc files. A remote attacker can silently download a potentially dangerous file to the user's system.

The vulnerability affects macOS operating system only.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 9.0.1 - 91.2.1

CPE2.3

External links

https://www.mozilla.org/en-US/security/advisories/mfsa2021-50/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

9) Buffer overflow

EUVDB-ID: #VU59147

Risk: High

CVSSv4.0: 5.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2021-43529

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when handling DER-encoded DSA or RSA-PSS signatures within Mozilla NSS library, as used in Mozilla Thunderbird. A remote attacker can send specially crafted emails with signatures encoded within CMS, S/MIME, PKCS #7, or PKCS #12, trigger a heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note, this vulnerability is described separately from #VU58477 (CVE-2021-43527), as Mozilla has decided to issue different patches for Thunderbird and NSS library.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 9.0 - 91.2.1

CPE2.3

External links

https://www.openwall.com/lists/oss-security/2021/12/01/6
https://bugzilla.mozilla.org/show_bug.cgi?id=1738501
https://bugs.chromium.org/p/project-zero/issues/detail?id=2237

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.