It was found that the GnuTLS implementation of HMAC-SHA-384 was vulnerable to a Lucky thirteen style attack.
It was found that the GnuTLS implementation of HMAC-SHA-384 was vulnerable to a Lucky thirteen style attack. Remote attackers could use this flaw to conduct distinguishing attacks and plain text recovery attacks via statistical analysis of timing data using crafted packets.
- Published
- Aug 22, 2018
- Updated
- Jun 16, 2026
- EPSS
- 3.6% · 89th percentile
- CWE
- CWE-385
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
24
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 3.6%
CNA vs NVD score
- NVD
- 5.9
- CNA · redhat
- 5.9
- agree
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| gnu | gnutls | cpe:2.3:a:gnu:gnutls |
| redhat | enterprise linux desktop | cpe:2.3:o:redhat:enterprise_linux_desktop |
| redhat | enterprise linux server | cpe:2.3:o:redhat:enterprise_linux_server |
| redhat | enterprise linux workstation | cpe:2.3:o:redhat:enterprise_linux_workstation |
| canonical | ubuntu linux | cpe:2.3:o:canonical:ubuntu_linux |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- canonical ubuntu linux16.04
- canonical ubuntu linux18.04
- canonical ubuntu linux18.10
- canonical ubuntu linux19.04
- debian debian linux8.0
- fedoraproject fedora31
- fedoraproject fedora32
- gnu gnutlsbefore 3.6.12
- redhat enterprise linux desktop7.0
- redhat enterprise linux server7.0
- redhat enterprise linux workstation7.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
[UNKNOWN] gnutls
- n/aaffected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | gnutls28 | before 3.5.19-1 | 3.5.19-1 |
| Debian:8 | gnutls28 | before 3.3.30-0+deb8u1 | 3.3.30-0+deb8u1 |
| Red Hat:enterprise_linux:7::client | gnutls | before 0:3.3.29-8.el7 | 0:3.3.29-8.el7 |
| Red Hat:enterprise_linux:7::client | gnutls-c++ | before 0:3.3.29-8.el7 | 0:3.3.29-8.el7 |
| Red Hat:enterprise_linux:7::client | gnutls-dane | before 0:3.3.29-8.el7 | 0:3.3.29-8.el7 |
| Red Hat:enterprise_linux:7::client | gnutls-debuginfo | before 0:3.3.29-8.el7 | 0:3.3.29-8.el7 |
| Red Hat:enterprise_linux:7::client | gnutls-devel | before 0:3.3.29-8.el7 | 0:3.3.29-8.el7 |
| Red Hat:enterprise_linux:7::client | gnutls-utils | before 0:3.3.29-8.el7 | 0:3.3.29-8.el7 |
| SUSE:Linux Enterprise Desktop 12 SP3 | gnutls | before 3.3.27-3.3.1 | 3.3.27-3.3.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 | gnutls | before 3.6.2-6.3.1 | 3.6.2-6.3.1 |
| SUSE:OpenStack Cloud 7 | gnutls | before 3.2.15-18.6.1 | 3.2.15-18.6.1 |
Same product
gnu: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-5334Double free vulnerability in the gnutls_x509_ext_import_proxy function in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allows remote attacker49Plan
- CVE-2019-3829A vulnerability was found in gnutls versions from 3.5.8 before 3.6.7.48Plan
- CVE-2008-1948The _gnutls_server_name_recv_params function in lib/ext_server_name.c in libgnutls in gnutls-serv in GnuTLS before 2.2.4 does not properly c44Plan
- CVE-2017-5337Multiple heap-based buffer overflows in the read_attribute function in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allow remote attackers to41Plan
- CVE-2017-5336Stack-based buffer overflow in the cdk_pk_get_keyid function in lib/opencdk/pubkey.c in GnuTLS before 3.3.26 and 3.5.x before 3.5.8 allows r41Plan
- CVE-2021-20232A flaw was found in gnutls.40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:gnutls28 | 3.5.19-1 · Debian:12 | Package registry (OSV) |
| red hat:gnutls | 0:3.3.29-8.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:gnutls-c++ | 0:3.3.29-8.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:gnutls-dane | 0:3.3.29-8.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:gnutls-debuginfo | 0:3.3.29-8.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:gnutls-devel | 0:3.3.29-8.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| red hat:gnutls-utils | 0:3.3.29-8.el7 · Red Hat:enterprise_linux:7::client | Package registry (OSV) |
| suse:gnutls | 3.2.15-18.6.1 · SUSE:OpenStack Cloud 7 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-385 · Covert Timing ChannelCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- www.securityfocus.com/bid/105138
- access.redhat.com/errata/RHSA-2018:3050
- access.redhat.com/errata/RHSA-2018:3505
- bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10845
- eprint.iacr.org/2018/747
- gitlab.com/gnutls/gnutls/merge_requests/657
- lists.debian.org/debian-lts-announce/2018/10/msg00022.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ILMOWPKMTZAIMK5F32TUMO34XCABUCFJ/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WDYY3R4F5CUTFAMXH2C5NKYFVDEJLTT7/
- usn.ubuntu.com/3999-1/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.