CVE-2019-11841
golang-go.crypto - security update
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.
How to fix CVE-2019-11841
To remediate CVE-2019-11841, upgrade the affected package to a fixed version below.
- —upgrade to 1:0.0~git20200221.2aa609c-1 or later
- —upgrade to 0.0~hg190-1+deb8u2 or later
- —upgrade to 0.0.0-20190424203555-c05e17bb3b2d or later
- —upgrade to 0.0.0-20190424203555-c05e17bb3b2d or later
Is CVE-2019-11841 being exploited?
Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0, < 1:0.0~git20200221.2aa609c-1
- from 0, < 0.0~hg190-1+deb8u2
- from 0, < 0.0.0-20190424203555-c05e17bb3b2d
- from 0, < 0.0.0-20190424203555-c05e17bb3b2d
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |