What’s Vulnerable › Vulnerabilities

CVE-2021-31439

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-05-21 · updated 2026-06-17
• Weakness: CWE-122

Description

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Synology DiskStation Manager. Authentication is not required to exploit this vulnerablity. The specific flaw exists within the processing of DSI structures in Netatalk. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-12326.

Affected products

• Debian Linux: 10.0, 11.0
• Netatalk: before 3.1.13 — fixed in 3.1.13
• Synology DiskStation Manager: from 6.2 before 6.2.3-25426-3 — fixed in 6.2.3-25426-3

How to fix

Upgrade to a fixed version: Netatalk 3.1.13; Synology DiskStation Manager 6.2.3-25426-3. Check the vendor advisory for mitigations.

References

• https://lists.debian.org/debian-lts-announce/2023/05/msg00018.html
• https://security.gentoo.org/glsa/202311-02
• https://www.debian.org/security/2023/dsa-5503
• https://www.synology.com/zh-hk/security/advisory/Synology_SA_20_26
• https://www.zerodayinitiative.com/advisories/ZDI-21-492/
• https://lists.debian.org/debian-lts-announce/2023/05/msg00018.html
• https://security.gentoo.org/glsa/202311-02
• https://www.debian.org/security/2023/dsa-5503
• https://www.synology.com/zh-hk/security/advisory/Synology_SA_20_26
• https://www.zerodayinitiative.com/advisories/ZDI-21-492/

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