CVE-2021-45756: asus rt-ac5300_firmware Classic Buffer Overflow
CVSS: 9.8v3.1CriticalModified
Published 23-03-2022Last modified 09-07-2026
Vulnerability summary
CVE-2021-45756 is a critical (CVSS 9.8) Classic Buffer Overflow vulnerability in asus rt-ac5300_firmware. EPSS estimates a 1.24% chance of exploitation in the next 30 days, higher than 68.7% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
9.8/10
010
Critical · v3.1 (NVD)EPSS score
1.24%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github
Timeline
- 23-03-2022PublishedVulnerability first disclosed.
- 09-07-2026Last modifiedVulnerability information updated.
Description
Asus RT-AC68U <3.0.0.4.385.20633 and RT-AC5300 <3.0.0.4.384.82072 are affected by a buffer overflow in blocking_request.cgi.
CVSS metrics
2 scores · 1 source · 2 versionsCritical 9.8Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSourcesSingle source
High 7.5Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
1.24%
Chance of exploitation in the next 30 days
Percentile
69%
Versus all other CVEs
30-day change
0.00 pp
From 1.24% on 19-09-2026
19-09-202619-10-2026
EPSS score1.24%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundAsus
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Asus2 products
- rt-ac5300_firmware< 3.0.0.4.384.82072
- rt-ac68u_firmware< 3.0.0.4.385.20633
1 vendor · 2 products