CVE-2019-11841

 

Published at: - 22-05-2019 07:29

Last modified: - 03-05-2022 04:22

Total changes: - 3

Description

A message-forgery issue was discovered in crypto/openpgp/clearsign/clearsign.go in supplementary Go cryptography libraries 2019-03-25. According to the OpenPGP Message Format specification in RFC 4880 chapter 7, a cleartext signed message can contain one or more optional "Hash" Armor Headers. The "Hash" Armor Header specifies the message digest algorithm(s) used for the signature. However, the Go clearsign package ignores the value of this header, which allows an attacker to spoof it. Consequently, an attacker can lead a victim to believe the signature was generated using a different message digest algorithm than what was actually used. Moreover, since the library skips Armor Header parsing in general, an attacker can not only embed arbitrary Armor Headers, but also prepend arbitrary text to cleartext messages without invalidating the signatures.

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

 

Verification logic

 

Reference

• https://sec-consult.com/en/blog/advisories/cleartext-message-spoofing-in-go-cryptography-libraries-cve-2019-11841/
• https://sec-consult.com/
• https://go.googlesource.com/crypto/
• http://packetstormsecurity.com/files/152840/Go-Cryptography-Libraries-Cleartext-Message-Spoofing.html
• [debian-lts-announce] 20190913 [SECURITY] [DLA 1920-1] golang-go.crypto security update-Mailing List, Third Party Advisory
• [debian-lts-announce] 20201007 [SECURITY] [DLA 2402-1] golang-go.crypto security update-Mailing List, Third Party Advisory

 

Keywords

NVD

 

CVE-2019-11841

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures