CVE-2021-33560
Publication date 8 June 2021
Last updated 24 July 2024
Ubuntu priority
Cvss 3 Severity Score
Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm, and the window size is not chosen appropriately. This, for example, affects use of ElGamal in OpenPGP.
Status
Package | Ubuntu Release | Status |
---|---|---|
libgcrypt20 | 24.04 LTS noble |
Fixed 1.8.7-5ubuntu2
|
22.04 LTS jammy |
Fixed 1.8.7-5ubuntu2
|
|
20.04 LTS focal |
Fixed 1.8.5-5ubuntu1.1
|
|
18.04 LTS bionic |
Fixed 1.8.1-4ubuntu1.3
|
|
16.04 LTS xenial |
Fixed 1.6.5-2ubuntu0.6+esm1
|
|
14.04 LTS trusty | Not in release |
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mdeslaur
This CVE was originally for the issue that is now CVE=2021-40528 but somehow got switched to the exponent blinding issue instead. The fix to add exponent blinding appears to only have been added to 1.9.x but never backported to 1.8.x, contrary to the CVE description The commit below was never backported to 1.8.x because the upstream developers consider this hardening and not a security issue.
Patch details
Package | Patch details |
---|---|
libgcrypt20 |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 7.5 · High |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | None |
Scope | Unchanged |
Confidentiality | High |
Integrity impact | None |
Availability impact | None |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
References
Related Ubuntu Security Notices (USN)
- USN-5080-1
- Libgcrypt vulnerabilities
- 16 September 2021
- USN-5080-2
- Libgcrypt vulnerabilities
- 16 September 2021