PatchTheCVECVE-2021-31703: Frontier ichris through 5.18 allows users to upload malicious executable files that might later be downloaded
CVE-2021-31703 is a critical-severity flaw (CVSS 9.8) affecting ichris. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Frontier ichris through 5.18 allows users to upload malicious executable files that might later be downloaded and run by any client user.
Why this priority
- Critical severity
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.2% (top 31%) |
| CISA exploited list | No |
| Weakness | CWE-434 |
| Published | 2021-05-29 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-31703?
ichris: upgrade to newer than 5.18. Exact commands for each OS are on this page.
Is CVE-2021-31703 being exploited?
CVE-2021-31703 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-31703 affect?
CVE-2021-31703 affects ichris. Severity is critical (CVSS 9.8). Frontier ichris through 5.18 allows users to upload malicious executable files that might later be downloaded and run by any client user.
How urgent is CVE-2021-31703?
Priority 57/100. Critical severity; Remotely exploitable, no login, no user action
Related CVEs
- CVE-2021-31702 HIGH 7.5 UPGRADE Frontier ichris through 5.18 mishandles making a DNS request for the hostname in the HTTP Host header, as demo