CVE-2019-11841 SUSE CVE security@suse.de SUSE Security Team SUSE CVE-2019-11841 Interim 1 6 2025-02-17T02:04:59Z current 2021-05-30T14:28:26Z 2025-02-17T02:04:59Z cve-database/bin/generate-cvrf-cve.pl 2020-12-27T01:00:00Z CVE-2019-11841 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. The CVRF data is provided by SUSE under the Creative Commons License 4.0 with Attribution (CC-BY-4.0). https://www.suse.com/support/security/rating/ SUSE Security Ratings 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. CVE-2019-11841 moderate 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N