In Realtek eCos RSDK 1.5.7p1 and MSDK 4.9.4p1, the SIP ALG function that rewrites SDP data has a stack-based buffer overflow. This allows an attacker to remotely execute code without authentication via a crafted SIP packet that contains malicious SDP data.
Conclusion & alert: CVE-2022-27255 is rated High Risk (67.3/100): CVSS Critical severity, with high exploitation likelihood (EPSS 15.24%, 95th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-03-25 | 21.58% | 15.24% | -6.33% |
| 2 | 2026-03-03 | 25.00% | 21.58% | -3.42% |
| 3 | 2026-03-01 | — | 25.00% | — |
Full EPSS history (35 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | [email protected] |
| 7.5 | 2.0 | HIGH |
|
10.0 | 6.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| realtek | ecos_rsdk_firmware | 1.5.7p1 | cpe:2.3:o:realtek:ecos_rsdk_firmware:1.5.7p1:*:*:*:*:*:*:* |
| realtek | ecos_msdk_firmware | 4.9.4p1 | cpe:2.3:o:realtek:ecos_msdk_firmware:4.9.4p1:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://forum.defcon.org/node/241835 | Third Party Advisory |
| https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2022-27255.pdf | Vendor Advisory |