libgcrypt: last-level cache side-channel attack
Published Nov 29, 2019
5.9
MEDIUMCVSS 3.1
EPSS 1.95%
Description
The mpi_powm function in Libgcrypt before 1.6.3 and GnuPG before 1.4.19 allows attackers to obtain sensitive information by leveraging timing differences when accessing a pre-computed table during modular exponentiation, related to a "Last-Level Cache Side-Channel Attack."
Affected products
-
- Version before 1.4.19StatusaffectedConstraints-
- Version
-
- Version before 1.6.3StatusaffectedConstraints-
- Version
Configuration 2
- 7.0
- 8.0
No data.
Red Hat Enterprise Linux 5
gnupg
Will not fix
Red Hat Enterprise Linux 5
gnupg2
Will not fix
Red Hat Enterprise Linux 5
libgcrypt
Will not fix
Red Hat Enterprise Linux 6
gnupg2
Will not fix
Red Hat Enterprise Linux 6
libgcrypt
Will not fix
Red Hat Enterprise Linux 7
gnupg2
Will not fix
Red Hat Enterprise Linux 7
libgcrypt
Will not fix
Red Hat Enterprise Virtualization 3
mingw-virt-viewer
Fix deferred
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | gnupg | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | gnupg2 | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | libgcrypt | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | gnupg2 | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | libgcrypt | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | gnupg2 | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | libgcrypt | Will not fix | n/a |
| Red Hat Enterprise Virtualization 3 | mingw-virt-viewer | Fix deferred | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Red Hat Product Security has rated this issue as having low security impact, a future update may address this flaw in the libgcrypt and gnupg2 packages. The attack leading to this flaw, is difficult to conduct in practice especially for cross-vm environments, mainly because the attacker needs to run their timing attack script at the exact same time decryption runs on the victim machine. Also this is essentially a chosen ciphertext attack because the attacker provides the ciphertext which the victim needs to be decrypt. Such actions only work when there is sufficient social engineer involved.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
No CVSS v3.0 score for this CVE.
AV:N/AC:M/Au:N/C:P/I:N/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2022–2026- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (10 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 1.95% (0.01952) | 79.52th | v5 (v2026.06.15) |
| Jun 15, 2026 | 1.95% (0.01952) | 77.56th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.55% (0.00551) | 66.01th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.30% (0.00301) | 70.39th | v3 (v2023.03.01) |
| Feb 8, 2024 | 0.26% (0.00255) | 64.42th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.26% (0.00255) | 61.59th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.02% (0.01018) | 40.69th | v2 (v2022.01.01) |
| Sep 10, 2022 | 1.02% (0.01018) | 38.88th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.02% (0.01018) | 36.86th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.02% (0.01018) | 19.50th | v2 (v2022.01.01) |
References (9)
- http://www.debian.org/security/2015/dsa-3184 x_refsource_MISCThird Party Advisory
- http://www.debian.org/security/2015/dsa-3185 x_refsource_MISCThird Party Advisory
- https://access.redhat.com/security/cve/CVE-2015-0837 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1198147 Issue Tracking
- https://ieeexplore.ieee.org/document/7163050 x_refsource_MISCThird Party Advisory
- https://lists.gnupg.org/pipermail/gnupg-announce/2015q1/000363.html x_refsource_CONFIRMMailing ListVendor Advisory
- https://lists.gnupg.org/pipermail/gnupg-announce/2015q1/000364.html x_refsource_CONFIRMMailing ListVendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2015-0837
- https://www.cve.org/CVERecord?id=CVE-2015-0837
| Link | Providers | Tags |
|---|---|---|
| http://www.debian.org/security/2015/dsa-3184 | x_refsource_MISCThird Party Advisory | |
| http://www.debian.org/security/2015/dsa-3185 | x_refsource_MISCThird Party Advisory | |
| https://access.redhat.com/security/cve/CVE-2015-0837 | Vendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1198147 | Issue Tracking | |
| https://ieeexplore.ieee.org/document/7163050 | x_refsource_MISCThird Party Advisory | |
| https://lists.gnupg.org/pipermail/gnupg-announce/2015q1/000363.html | x_refsource_CONFIRMMailing ListVendor Advisory | |
| https://lists.gnupg.org/pipermail/gnupg-announce/2015q1/000364.html | x_refsource_CONFIRMMailing ListVendor Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2015-0837 | ||
| https://www.cve.org/CVERecord?id=CVE-2015-0837 |
Change history (0)
No recorded changes yet.