CVE-2026-4408

Summary

A flaw was found in Samba. A remote attacker can exploit a misconfiguration in Samba file servers and classic domain controllers that use the "check password script" feature. If this script is configured with the %u substitution character, the client-controlled username is passed without proper escaping of shell meta-characters. This vulnerability allows an attacker to achieve remote command execution on the affected system. This issue primarily affects non-standard configurations where the "check password script" is used with %u and the samba-dcerpcd service is started as a system service.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat Enterprise Linux 100:4.23.5-109.el10_2 < *unaffected
Red HatRed Hat Enterprise Linux 10.0 Extended Update Support0:4.21.3-114.el10_0.1 < *unaffected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Support0:4.10.16-26.el7_9.1 < *unaffected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Support0:4.10.16-26.el7_9.1 < *unaffected
Red HatRed Hat Enterprise Linux 80:4.19.4-16.el8_10 < *unaffected
Red HatRed Hat Enterprise Linux 80:4.19.4-16.el8_10 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support0:4.13.3-12.el8_4.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On0:4.13.3-12.el8_4.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support0:4.15.5-16.el8_6.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On0:4.15.5-16.el8_6.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Service0:4.17.5-7.el8_8.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutions0:4.17.5-7.el8_8.1 < *unaffected
Red HatRed Hat Enterprise Linux 90:4.23.5-10.el9_8 < *unaffected
Red HatRed Hat Enterprise Linux 90:4.23.5-10.el9_8 < *unaffected
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP Solutions0:4.17.5-105.el9_2.5 < *unaffected
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP Solutions0:4.19.4-105.el9_4.4 < *unaffected
Red HatRed Hat Enterprise Linux 9.6 Extended Update Support0:4.21.3-14.el9_6.1 < *unaffected
Red HatRed Hat OpenShift Container Platform 4.194.19.9.6.202606241344-0 < *unaffected
Red HatRed Hat OpenShift Container Platform 4.204.20.9.6.202606241928-0 < *unaffected
Red HatRed Hat OpenShift Container Platform 4.214.21.9.6.202606241859-0 < *unaffected

Weaknesses

  • CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Workarounds

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

samba: Remote Code Execution in SAMR

Additional References

References