CVE-2019-11841 — MEDIUM (5.9)

Vulnerability 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.

CVSS Score

5.9

MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

NONE

Affected Products

Vendor	Product	Versions
Golang	Crypto	2019-03-25
Debian	Debian Linux	8.0

Related Weaknesses (CWE)

CWE-347

References

http://packetstormsecurity.com/files/152840/Go-Cryptography-Libraries-Cleartext-ExploitThird Party AdvisoryVDB Entry
https://go.googlesource.com/crypto/ProductThird Party Advisory
https://lists.debian.org/debian-lts-announce/2019/09/msg00011.htmlMailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/10/msg00014.htmlMailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2023/06/msg00017.html
https://sec-consult.com/Third Party Advisory
https://sec-consult.com/en/blog/advisories/cleartext-message-spoofing-in-go-crypExploitThird Party Advisory
http://packetstormsecurity.com/files/152840/Go-Cryptography-Libraries-Cleartext-ExploitThird Party AdvisoryVDB Entry
https://go.googlesource.com/crypto/ProductThird Party Advisory
https://lists.debian.org/debian-lts-announce/2019/09/msg00011.htmlMailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2020/10/msg00014.htmlMailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2023/06/msg00017.html
https://sec-consult.com/Third Party Advisory
https://sec-consult.com/en/blog/advisories/cleartext-message-spoofing-in-go-crypExploitThird Party Advisory

FAQ

What is CVE-2019-11841?

CVE-2019-11841 is a vulnerability with a CVSS score of 5.9 (MEDIUM). 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...

How severe is CVE-2019-11841?

CVE-2019-11841 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2019-11841?

Check the references section above for vendor advisories and patch information. Affected products include: Golang Crypto, Debian Debian Linux.