CVE-2020-27539
CVSS v3
9.8
CRITICAL
EPSS Score
1.3 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
Heap overflow with full parsing of HTTP respose in Rostelecom CS-C2SHW 5.0.082.1. AgentUpdater service has a self-written HTTP parser and builder. HTTP parser has a heap buffer overflow (OOB write). In default configuration camera parses responses only from HTTPS URLs from config file, so vulnerable code is unreachable and one more bug required to reach it.
Technical details
- Published
- 2021-01-26
Frequently asked questions
What is CVE-2020-27539?
Heap overflow with full parsing of HTTP respose in Rostelecom CS-C2SHW 5.0.082.1. AgentUpdater service has a self-written HTTP parser and builder. HTTP parser has a heap buffer overflow (OOB write). In default configuration camera parses responses only from HTTPS URLs from config file, so vulnerable code is unreachable and one more bug required to reach it.
Is CVE-2020-27539 actively exploited?
Active exploitation of CVE-2020-27539 has not been confirmed. Its EPSS score was 1.3% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2020-27539?
CVE-2020-27539 has a CVSS v3 base score of 9.8 (CRITICAL severity).
Is CVE-2020-27539 affecting your environment?
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