# CVE-2018-20102: haproxy: An out-of-bounds read in dns_validate_dns_response in dns.c was discovered in HAProxy through 1.8.14

CVE-2018-20102 is fixed in 2 products on 1 platform, first by haproxy 1.8.8-1ubuntu0.3, released December 30, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-20102
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0415
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Dec 11, 2018

## Description

An out-of-bounds read in dns_validate_dns_response in dns.c was discovered in HAProxy through 1.8.14. Due to a missing check when validating DNS responses, remote attackers might be able read the 16 bytes corresponding to an AAAA record from the non-initialized part of the buffer, possibly accessing anything that was left on the stack, or even past the end of the 8193-byte buffer, depending on the value of accepted_payload_size.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | haproxy Ubuntu 18.04.6 LTS (bionic) | 1.8.8-1ubuntu0.3 | [haproxy 1.8.8-1ubuntu0.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-haproxy-1.8.8-1ubuntu0.3.md) | Dec 30, 2018 |
| Linux | vim-haproxy Ubuntu 18.04.6 LTS (bionic) | 1.8.8-1ubuntu0.3 | [vim-haproxy 1.8.8-1ubuntu0.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-vim-haproxy-1.8.8-1ubuntu0.3.md) | Dec 30, 2018 |

---

Data as of 2026-11-07T06:34:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo