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Libgit2 CVE-2023-22742

MEDIUM
Improper Verification of Cryptographic Signature (CWE-347)
2023-01-20 security-advisories@github.com
5.9
CVSS 3.1 · NVD
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Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A04:2025 - Cryptographic Failures
ASVS 5.0
V11 - Cryptography Signature verification
Impact

CVSS score of 5.9 (MEDIUM). Attack characteristics: network attack vector, high complexity, no privileges required, no user interaction not required.

Exploit ScenarioDerived

This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the medium-severity affected system.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.6% exploitation probability (EPSS)

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AnalysisAI

libgit2 is a cross-platform, linkable library implementation of Git. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Affected Packages

cargo git2 fix: 0.16.1
cargo libgit2-sys fix: 0.13.5, 0.14.2

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 2 packages in cargo

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified under CWE-347. libgit2 is a cross-platform, linkable library implementation of Git. When using an SSH remote with the optional libssh2 backend, libgit2 does not perform certificate checking by default. Prior versions of libgit2 require the caller to set the certificate_check field of libgit2's git_remote_callbacks structure - if a certificate check callback is not set, libgit2 does not perform any certificate checking. This means that by default - without configuring a certificate check callback, clients will not perform validation on the server SSH keys and may be subject to a man-in-the-middle attack. Users are encouraged to upgrade to v1.4.5 or v1.5.1. Users unable to upgrade should ensure that all relevant certificates are manually checked. Affected products include: Libgit2.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 5.9 MEDIUM
AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

DescriptionNVD

libgit2 is a cross-platform, linkable library implementation of Git. When using an SSH remote with the optional libssh2 backend, libgit2 does not perform certificate checking by default. Prior versions of libgit2 require the caller to set the certificate_check field of libgit2's git_remote_callbacks structure - if a certificate check callback is not set, libgit2 does not perform any certificate checking. This means that by default - without configuring a certificate check callback, clients will not perform validation on the server SSH keys and may be subject to a man-in-the-middle attack. Users are encouraged to upgrade to v1.4.5 or v1.5.1. Users unable to upgrade should ensure that all relevant certificates are manually checked.

Threat Intelligence Overview

EPSS Score
0.6%
Top 56% exploitable
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.6%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

31
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +30
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Affected Products (CPE)NVD

cpe:2.3:a:libgit2:libgit2:*:*:*:*:*:*:*:*
cpe:2.3:a:libgit2:libgit2:1.5.0:*:*:*:*:*:*:*
CVE-2018-15501 HIGH POC
7.5 Aug 18

In ng_pkt in transports/smart_pkt.c in libgit2 before 0.26.6 and 0.27.x before 0.27.4, a remote attacker can send a craf

CVE-2016-10128 CRITICAL
9.8 Mar 24

Buffer overflow in the git_pkt_parse_line function in transports/smart_pkt.c in the Git Smart Protocol support in libgit

CVE-2020-12279 CRITICAL
9.8 Apr 27

An issue was discovered in libgit2 before 0.28.4 and 0.9x before 0.99.0. Rated critical severity (CVSS 9.8), this vulner

CVE-2020-12278 CRITICAL
9.8 Apr 27

An issue was discovered in libgit2 before 0.28.4 and 0.9x before 0.99.0. Rated critical severity (CVSS 9.8), this vulner

CVE-2016-10129 HIGH
7.5 Mar 24

The Git Smart Protocol support in libgit2 before 0.24.6 and 0.25.x before 0.25.1 allows remote attackers to cause a deni

CVE-2018-10887 HIGH
8.1 Jul 10

A flaw was found in libgit2 before version 0.27.3. Rated high severity (CVSS 8.1), this vulnerability is remotely exploi

CVE-2018-10888 MEDIUM
6.5 Jul 10

A flaw was found in libgit2 before version 0.27.3. Rated medium severity (CVSS 6.5), this vulnerability is remotely expl

CVE-2018-8099 MEDIUM
6.5 Mar 14

Incorrect returning of an error code in the index.c:read_entry() function leads to a double free in libgit2 before v0.26

CVE-2018-8098 MEDIUM
6.5 Mar 14

Integer overflow in the index.c:read_entry() function while decompressing a compressed prefix length in libgit2 before v

CVE-2016-10130 MEDIUM
5.9 Mar 24

The http_connect function in transports/http.c in libgit2 before 0.24.6 and 0.25.x before 0.25.1 might allow man-in-the-

CVE-2016-8569 MEDIUM
5.5 Feb 03

The git_oid_nfmt function in commit.c in libgit2 before 0.24.3 allows remote attackers to cause a denial of service (NUL

CVE-2016-8568 MEDIUM
5.5 Feb 03

The git_commit_message function in oid.c in libgit2 before 0.24.3 allows remote attackers to cause a denial of service (

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