# CVE-2020-17437: iscsiuio: An issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products

CVE-2020-17437 is fixed in 2 products on 1 platform, first by iscsiuio 2.0.874-5ubuntu2.11+esm1, released November 30, 2020. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2020-17437
- Priority: Routine
- CVSS: n/a (Low)
- EPSS: 0.0286
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Nov 30, 2020

## Description

An issue was discovered in uIP 1.0, as used in Contiki 3.0 and other products. When the Urgent flag is set in a TCP packet, and the stack is configured to ignore the urgent data, the stack attempts to use the value of the Urgent pointer bytes to separate the Urgent data from the normal data, by calculating the offset at which the normal data should be present in the global buffer. However, the length of this offset is not checked; therefore, for large values of the Urgent pointer bytes, the data pointer can point to memory that is way beyond the data buffer in uip_process in uip.c.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | iscsiuio Ubuntu 18.04.6 LTS (bionic) | 2.0.874-5ubuntu2.11+esm1 | [iscsiuio 2.0.874-5ubuntu2.11+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-iscsiuio-2.0.874-5ubuntu2.11-esm1.md) | Nov 30, 2020 |
| Linux | iscsiuio Ubuntu 20.04 LTS (focal) | 2.0.874-7.1ubuntu6.4 | [iscsiuio 2.0.874-7.1ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-iscsiuio-2.0.874-7.1ubuntu6.4.md) | Nov 30, 2020 |
| Linux | open-iscsi Ubuntu 18.04.6 LTS (bionic) | 2.0.874-5ubuntu2.11+esm1 | [open-iscsi 2.0.874-5ubuntu2.11+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-open-iscsi-2.0.874-5ubuntu2.11-esm1.md) | Nov 30, 2020 |
| Linux | open-iscsi Ubuntu 20.04 LTS (focal) | 2.0.874-7.1ubuntu6.4 | [open-iscsi 2.0.874-7.1ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-open-iscsi-2.0.874-7.1ubuntu6.4.md) | Nov 30, 2020 |

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Data as of 2026-11-08T00:53:09Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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