Cyber Resilience

CVE-2023-28796

Zscaler Client Connector ≤ 1.3.1.6

Published
23 October 2023
Modified
21 November 2024
CVSS Score v3.1 7.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
EPSS Score 0.0018 8th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2023-28796 is a high-severity Code Injection (CWE-94) vulnerability in Zscaler Client Connector. Its CVSS base score is 7.1 (High).

Operationally, ranked at the 8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Improper Verification of Cryptographic Signature vulnerability in Zscaler Client Connector on Linux allows Code Injection. This issue affects Zscaler Client Connector for Linux: before 1.3.1.6.

CWE(s)

Related Threats

CVEs Like This One

CVE-2024-23460Same product: Zscaler Client Connector
CVE-2023-28804Same product: Zscaler Client Connector
CVE-2024-23480Same product: Zscaler Client Connector
CVE-2024-23456Same product: Zscaler Client Connector
CVE-2023-28806Same product: Zscaler Client Connector
CVE-2023-28793Same product: Zscaler Client Connector
CVE-2023-28801Same vendor: Zscaler
CVE-2025-7937Shared CWE-347
CVE-2024-6936Shared CWE-94
CVE-2026-34965Shared CWE-94

Affected Assets

zscaler
client connector
≤ 1.3.1.6

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 14 hardening rules · 5 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.3.1

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-347

Requires verification of digital signatures using organization-approved certificates before installation, directly preventing improper verification of cryptographic signatures.

addresses: CWE-347

Component authenticity commonly depends on cryptographic signatures; the control enforces proper verification of those signatures.

addresses: CWE-347

PKI certificates under an approved policy require cryptographic signature verification on issuance and validation.

addresses: CWE-347

Requires cryptographic signatures on authoritative data and support for verifying the chain of trust.

addresses: CWE-347

Mandates verification of cryptographic signatures (e.g., DNSSEC RRSIG) on resolution responses, addressing missing or bypassed signature checks.

addresses: CWE-94

Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.

addresses: CWE-94

Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.

addresses: CWE-94

Validates inputs used in dynamic code generation to block injected directives.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.DS-01 mostly match
prevents

Digital signatures are explicitly cited to protect integrity of data-at-rest, so proper verification directly mitigates the weakness.

PR.DS-02 mostly match
prevents

Digital signatures are explicitly cited to protect integrity of data-in-transit, so proper verification directly mitigates the weakness.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).

ID.RA-09 partial match
prevents

Requires assessing authenticity and integrity of acquired assets, which commonly relies on signature verification but is limited to pre-acquisition.

PR.DS-10 none match
prevents

PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Establishing approved cryptographic solutions and usage practices lowers the probability that signature-verification steps will be omitted or incorrectly implemented.

prevents

Banning unapproved code samples and unauthenticated web services, combined with secure-coding standards and SAST, prevents the dynamic generation or inclusion of attacker-supplied code.

none

Controls that restrict unauthorized or malicious code from being introduced via external networks or removable media limit opportunities for an attacker to inject and execute arbitrary code.

Hardening callouts derived

Configuration rules from DISA STIG baselines that reduce the attack surface for weaknesses of the type cited by this CVE. Derived transitively via CVE→CWE→STIG over `controls_xwalks` (authoritative rows only).

Oracle Linux 8 (2 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. via CWE-347
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-347
Oracle Linux 9 (2 rules)
  • V-271523 OL 9 must check the GPG signature of locally installed software packages before installation. via CWE-347
  • V-271525 OL 9 must have GPG signature verification enabled for all software repositories. via CWE-347
RHEL 8 (1 rule)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. via CWE-347
RHEL 9 (1 rule)
  • V-257822 RHEL 9 must have GPG signature verification enabled for all software repositories. via CWE-347

References