CVE-2019-8338 - Improper Verification of Cryptographic Signature

Severity

43%

Complexity

86%

Confidentiality

48%

The signature verification routine in the Airmail GPG-PGP Plugin, versions 1.0 (9) and earlier, does not verify the status of the signature at all, which allows remote attackers to spoof arbitrary email signatures by crafting a signed email with an invalid signature. Also, it does not verify the validity of the signing key, which allows remote attackers to spoof arbitrary email signatures by crafting a key with a fake user ID (email address) and injecting it into the user's keyring.

The signature verification routine in the Airmail GPG-PGP Plugin, versions 1.0 (9) and earlier, does not verify the status of the signature at all, which allows remote attackers to spoof arbitrary email signatures by crafting a signed email with an invalid signature. Also, it does not verify the validity of the signing key, which allows remote attackers to spoof arbitrary email signatures by crafting a key with a fake user ID (email address) and injecting it into the user's keyring.

CVSS 3.0 Base Score 5.9. CVSS Attack Vector: network. CVSS Attack Complexity: high. CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N).

CVSS 2.0 Base Score 4.3. CVSS Attack Vector: network. CVSS Attack Complexity: medium. CVSS Vector: (AV:N/AC:M/Au:N/C:N/I:P/A:N).

Demo Examples

Improper Verification of Cryptographic Signature

CWE-347

In the following code, a JarFile object is created from a downloaded file.


               
JarFile jf = new JarFile(f);

The JAR file that was potentially downloaded from an untrusted source is created without verifying the signature (if present). An alternate constructor that accepts a boolean verify parameter should be used instead.

Overview

First reported 5 years ago

2019-05-16 17:29:00

Last updated 5 years ago

2019-05-21 14:07:00

Affected Software

GPG-PGP Project GPG-PGP for Airmail

airmail

References

http://packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.html

Third Party Advisory, VDB Entry

20190430 OpenPGP and S/MIME signature forgery attacks in multiple email clients

Mailing List, Third Party Advisory

https://github.com/Airmail/AirmailPlugIn-Framework/commits/master

Patch, Third Party Advisory

https://github.com/RUB-NDS/Johnny-You-Are-Fired

Third Party Advisory

https://github.com/RUB-NDS/Johnny-You-Are-Fired/blob/master/paper/johnny-fired.pdf

Third Party Advisory

[oss-security] 20190430 Spoofing OpenPGP and S/MIME Signatures in Emails (multiple clients)

Mailing List, Third Party Advisory

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