# CVE-2017-7892: capnproto: Sandstorm Cap'n Proto before 0.5.3.1 allows remote crashes related to a compiler optimization

CVE-2017-7892 is fixed in 2 products on 1 platform, first by capnproto 0.6.1-1, released April 17, 2017. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2017-7892
- Priority: Routine
- CVSS: n/a (Low)
- EPSS: 0.0184
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 17, 2017

## Description

Sandstorm Cap'n Proto before 0.5.3.1 allows remote crashes related to a compiler optimization. A remote attacker can trigger a segfault in a 32-bit libcapnp application because Cap'n Proto relies on pointer arithmetic calculations that overflow. An example compiler with optimization that elides a bounds check in such calculations is Apple LLVM version 8.1.0 (clang-802.0.41). The attack vector is a crafted far pointer within a message.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | capnproto Ubuntu 18.04.6 LTS (bionic) | 0.6.1-1 | [capnproto 0.6.1-1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-capnproto-0.6.1-1.md) | Apr 17, 2017 |
| Linux | libcapnp-0.6.1 Ubuntu 18.04.6 LTS (bionic) | 0.6.1-1 | [libcapnp-0.6.1 0.6.1-1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libcapnp-0.6.1-0.6.1-1.md) | Apr 17, 2017 |

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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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo