🛡️ CVE-2023-4257 — zephyr

How this vulnerability can be exploited

This issue can be reached from an adjacent network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality low, integrity low, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

• Attack vector: Adjacent network — the attacker has to sit on the same local or logical network.
• Attack complexity: Low — the attack works reliably, with no preparation.
• Privileges required: None — an unauthenticated stranger can try it.
• User interaction: None — nobody has to be tricked into anything.
• Scope: Unchanged — the damage stays inside the vulnerable component.
• Confidentiality impact: Low — limited, and the attacker does not choose what is affected.
• Integrity impact: Low — limited, and the attacker does not choose what is affected.
• Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2023-4257 is classified as CWE-120: Classic Buffer Overflow. Input is copied into a fixed-size buffer without a length check, overwriting memory past the end of it.

Affected software

CVE-2023-4257 is recorded against 1 package.

• zephyr (fixed in 3.4.0)

Timeline and source

Published on 13 October 2023 and last revised on 17 June 2026. A public exploit is known to exist, which raises the urgency of patching considerably. Record sourced from NVD.

References

packetstormsecurity.com
seclists.org
www.openwall.com
github.com
packetstormsecurity.com
seclists.org
www.openwall.com
github.com

Other advisories for this package

zephyr has other advisories on record. If you are patching this one, these are worth checking on the same host:

• CVE-2026-11368 (7.1 High, published 4 Aug 2026)
• CVE-2026-10849 (8.2 High, published 3 Aug 2026)
• CVE-2026-10774 (2.4 Low, published 2 Aug 2026)
• CVE-2026-10848 (7.0 High, published 2 Aug 2026)
• CVE-2026-10773 (5.4 Medium, published 1 Aug 2026)
• CVE-2026-2411 (6.5 Medium, published 1 Aug 2026)
• CVE-2026-10686 (5.8 Medium, published 31 Jul 2026)
• CVE-2026-10685 (7.6 High, published 31 Jul 2026)

Same weakness in other software

These advisories are the same class of weakness (CWE-120: Classic Buffer Overflow) in other software:

• CVE-2019-5064 (8.0 High, published 9 Jul 2026)
• CVE-2022-29210 (5.0 Medium, published 6 Jul 2026)
• CVE-2021-41499 (8.0 High, published 2 Jul 2026)
• CVE-2022-29974 (4.3 Medium, published 9 Dec 2024)
• CVE-2022-20846 (4.3 Medium, published 15 Nov 2024)
• CVE-2022-32504 (9.8 Critical, published 14 May 2024)
• CVE-2022-24807 (6.5 Medium, published 16 Apr 2024)
• CVE-2022-24805 (6.5 Medium, published 16 Apr 2024)

Details

Affected Packages

References