A message-forgery issue was discovered in crypto/openpgp/clearsign/clearsign.go in…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-347.
Summary
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | golang.org/x/crypto (Go) | before 0.0.0-20190424203555-c05e17bb3b2d | 0.0.0-20190424203555-c05e17bb3b2d | Patch available | GHSA-x3jr-pf6g-c48f |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- golang.org/x/crypto (Go) Vendor— Affected before 0.0.0-20190424203555-c05e17bb3b2d Fixed in 0.0.0-20190424203555-c05e17bb3b2d Patch available GHSA-x3jr-pf6g-c48f
CPE configurations NVD · 3
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:golang:crypto:2019-03-25:*:*:*:*:*:*:* | 2019-03-25 | Vulnerable | Go standard library |
| cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
- cpe:2.3:a:golang:crypto:2019-03-25:*:*:*:*:*:*:* Versions 2019-03-25 Vulnerable ·Go standard library
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
Remediation
- Fix · GHSA-x3jr-pf6g-c48f golang.org/x/crypto (Go) Fixed in 0.0.0-20190424203555-c05e17bb3b2d Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2019-11841
- 2026-10-03 Alias added: GHSA-x3jr-pf6g-c48f
References
Exploit 2
Advisory 5
Other 8
- [debian-lts-announce] 20230616 [SECURITY] [DLA 3455-1] golang-go.crypto security update
- 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://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
Sources
- CVE-2019-11841 · CVE Program
- CVE-2019-11841 · NVD
- FIRST EPSS
- GHSA-x3jr-pf6g-c48f · GitHub Advisory Database · CC BY 4.0
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