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.
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References
History
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MITRE
Status: PUBLISHED
Assigner: mitre
Published: 2019-05-22T00:00:00
Updated: 2024-08-04T23:03:32.829Z
Reserved: 2019-05-09T00:00:00
Link: CVE-2019-11841
Vulnrichment
No data.
NVD
Status : Modified
Published: 2019-05-22T17:29:00.287
Modified: 2023-06-17T00:15:09.527
Link: CVE-2019-11841
Redhat
No data.