PatchTheCVECVE-2020-27540: Bash injection vulnerability and bypass of signature verification in Rostelecom CS-C2SHW 5.0.082.1
CVE-2020-27540 is a critical-severity flaw (CVSS 9.8) affecting cs-c2shw firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Bash injection vulnerability and bypass of signature verification in Rostelecom CS-C2SHW 5.0.082.1. The camera reads firmware update configuration from SD card file vc\version.json. fw-sign parameter and from this configuration is directly inserted into a bash command. Firmware update is run automatically if there is special file on the inserted SD card.
Why this priority
- Critical severity
- Public exploit reference
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.8% (top 42%) |
| CISA exploited list | No |
| Weakness | CWE-347 |
| Published | 2021-01-26 |
| 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-2020-27540?
cs-c2shw firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2020-27540 being exploited?
CVE-2020-27540 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-2020-27540 affect?
CVE-2020-27540 affects cs-c2shw firmware. Severity is critical (CVSS 9.8). Bash injection vulnerability and bypass of signature verification in Rostelecom CS-C2SHW 5.0.082.1. The camera reads firmware update configuration from SD card file vc\version.json. fw-sign parameter and from this configuration is directly
How urgent is CVE-2020-27540?
Priority 59/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action
Related CVEs
- CVE-2020-27542 MEDIUM 6.8 MITIGATE Rostelecom CS-C2SHW 5.0.082.1 is affected by: Bash command injection
- CVE-2020-27541 HIGH 7.5 MITIGATE Denial of Service vulnerability in Rostelecom CS-C2SHW 5.0.082.1
- CVE-2020-27539 CRITICAL 9.8 MITIGATE Heap overflow with full parsing of HTTP respose in Rostelecom CS-C2SHW 5.0.082.1