libgcrypt: Use of left-to-right sliding window method allows full RSA key recovery
Published Jul 26, 2018
6.8
MEDIUMCVSS 3.0
EPSS 3.84%
Description
libgcrypt before version 1.7.8 is vulnerable to a cache side-channel attack resulting into a complete break of RSA-1024 while using the left-to-right method for computing the sliding-window expansion. The same attack is believed to work on RSA-2048 with moderately more computation. This side-channel requires that attacker can run arbitrary software on the hardware where the private RSA key is used.
Affected products
-
- Version 1.7.8StatusaffectedConstraints-
- Version
Configuration 2
- 12.04
- 14.04
- 16.04
Configuration 3
- 8.0
- 9.0
No data.
Red Hat Enterprise Linux 5
libgcrypt
Will not fix
Red Hat Enterprise Linux 6
libgcrypt
Will not fix
Red Hat Enterprise Linux 7
libgcrypt
Will not fix
Red Hat Enterprise Virtualization 3
mingw-virt-viewer
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 5 | libgcrypt | Will not fix | n/a |
| Red Hat Enterprise Linux 6 | libgcrypt | Will not fix | n/a |
| Red Hat Enterprise Linux 7 | libgcrypt | Will not fix | n/a |
| Red Hat Enterprise Virtualization 3 | mingw-virt-viewer | Will not fix | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
This side-channel attack requires that the attacker can run arbitrary software on the hardware where the private RSA key is used. Allowing execute access to a box with private keys should be considered as an unsafe security practice, anyway. Thus in practice there are easier ways to access the private keys than to mount this side-channel attack. However, on boxes with virtual machines this attack may be used by one VM to steal private keys from another VM.
Metrics
No CVSS v4.0 score for this CVE.
No CVSS v3.1 score for this CVE.
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
1 other source (Red Hat) ▾
CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N
AV:N/AC:M/Au:N/C:P/I:N/A:N
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Dec 17, 2025 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (24 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 3.84% (0.03835) | 89.77th | v5 (v2026.06.15) |
| Jun 15, 2026 | 3.89% (0.03885) | 88.84th | v5 (v2026.06.15) |
| Jan 11, 2026 | 2.70% (0.02701) | 85.45th | v4 (v2025.03.14) |
| Oct 29, 2025 | 3.74% (0.03739) | 87.48th | v4 (v2025.03.14) |
| May 2, 2025 | 2.73% (0.02725) | 85.20th | v4 (v2025.03.14) |
| Mar 30, 2025 | 3.89% (0.03887) | 87.19th | v4 (v2025.03.14) |
| Mar 29, 2025 | 5.75% (0.05752) | 83.69th | v4 (v2025.03.14) |
| Mar 17, 2025 | 3.89% (0.03887) | 87.48th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.27% (0.00274) | 68.92th | v3 (v2023.03.01) |
| Feb 19, 2024 | 0.38% (0.00384) | 72.38th | v3 (v2023.03.01) |
| Jan 26, 2024 | 0.49% (0.00489) | 73.62th | v3 (v2023.03.01) |
| Dec 17, 2023 | 0.60% (0.00596) | 76.00th | v3 (v2023.03.01) |
| Nov 8, 2023 | 0.98% (0.00981) | 81.68th | v3 (v2023.03.01) |
| Jul 20, 2023 | 0.39% (0.00385) | 69.54th | v3 (v2023.03.01) |
| May 8, 2023 | 0.33% (0.00330) | 66.56th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.39% (0.00389) | 69.05th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.54% (0.01537) | 74.52th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.54% (0.01537) | 74.48th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.54% (0.01537) | 72.41th | v2 (v2022.01.01) |
| Feb 4, 2022 | 1.54% (0.01537) | 51.33th | v2 (v2022.01.01) |
| Feb 3, 2022 | 2.68% (0.02678) | 55.40th | v1 |
| Jan 6, 2022 | 2.68% (0.02678) | 54.96th | v1 |
| Sep 1, 2021 | 2.68% (0.02678) | 79.35th | v1 |
| Apr 14, 2021 | 2.68% (0.02678) | 0.00th | v1 |
References (16)
- http://www.securityfocus.com/bid/99338 vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
- http://www.securitytracker.com/id/1038915 vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
- https://access.redhat.com/security/cve/CVE-2017-7526 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1466265 Issue Tracking
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-7526 x_refsource_CONFIRMIssue TrackingPatchThird Party Advisory
- https://eprint.iacr.org/2017/627 x_refsource_MISCThird Party Advisory
- https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=78130828e9a140a9de4dafadbc844dbb64cb709a x_refsource_CONFIRM
- https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=8725c99ffa41778f382ca97233183bcd687bb0ce x_refsource_CONFIRM
- https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=e6a3dc9900433bbc8ad362a595a3837318c28fa9 x_refsource_CONFIRM
- https://lists.gnupg.org/pipermail/gnupg-announce/2017q2/000408.html mailing-listx_refsource_MLISTMailing ListVendor Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2017-7526
- https://usn.ubuntu.com/3733-1/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://usn.ubuntu.com/3733-2/ vendor-advisoryx_refsource_UBUNTUThird Party Advisory
- https://www.cve.org/CVERecord?id=CVE-2017-7526
- https://www.debian.org/security/2017/dsa-3901 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.debian.org/security/2017/dsa-3960 vendor-advisoryx_refsource_DEBIANThird Party Advisory
Change history (0)
No recorded changes yet.