CVE-2019-11841
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 1:0.0~git20200221.2aa609c-1 |
| sid | Fixed | 1:0.0~git20200221.2aa609c-1 |
| forky | Fixed | 1:0.0~git20200221.2aa609c-1 |
| bullseye | Fixed | 1:0.0~git20200221.2aa609c-1 |
| bookworm | Fixed | 1:0.0~git20200221.2aa609c-1 |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Go | golang.org/x/crypto | <0.0.0-20190424203555-c05e17bb3b2d | 0.0.0-20190424203555-c05e17bb3b2d |
References
- https://nvd.nist.gov/vuln/detail/CVE-2019-11841
- https://github.com/golang/crypto/commit/c05e17bb3b2dca130fc919668a96b4bec9eb9442
- https://github.com/golang/crypto/tree/master/openpgp/clearsign
- https://go-review.git.corp.google.com/c/crypto/+/173778
- https://go.googlesource.com/crypto/+/c05e17bb3b2dca130fc919668a96b4bec9eb9442
- https://groups.google.com/d/msg/golang-openpgp/6vdgZoTgbIY/K6bBY9z3DAAJ
- https://lists.debian.org/debian-lts-announce/2019/09/msg00011.html
- https://lists.debian.org/debian-lts-announce/2020/10/msg00014.html
- https://lists.debian.org/debian-lts-announce/2023/06/msg00017.html
- https://pkg.go.dev/vuln/GO-2023-1992
- https://web.archive.org/web/20201207161832/https://sec-consult.com/en/blog/advisories/cleartext-message-spoofing-in-go-cryptography-libraries-cve-2019-11841
- http://packetstormsecurity.com/files/152840/Go-Cryptography-Libraries-Cleartext-Message-Spoofing.html
- https://security-tracker.debian.org/tracker/CVE-2019-11841
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.