CVE-2021-35034: zyxel nbg6604_firmware Insufficient Session Expiration
CVSS: 9.1v3.1CriticalModified
Published 29-12-2021Last modified 04-08-2024
Vulnerability summary
CVE-2021-35034 is a critical (CVSS 9.1) Insufficient Session Expiration vulnerability in zyxel nbg6604_firmware. EPSS estimates a 1.04% chance of exploitation in the next 30 days, higher than 63.5% of scored vulnerabilities.
CVSS score
9.1/10
010
Critical · v3.1 (NVD)EPSS score
1.04%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 29-12-2021PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
An insufficient session expiration vulnerability in the CGI program of the Zyxel NBG6604 firmware could allow a remote attacker to access the device if the correct token can be intercepted.
CVSS metrics
3 scores · 2 sources · 2 versionsCritical 9.1Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NSources2 sources · 7.4–9.1
- CVE.orgCNA7.4HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NDiffers
Medium 6.4Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:P/I:P/A:NSourcesSingle source
EPSS trend
Probability
1.04%
Chance of exploitation in the next 30 days
Percentile
64%
Versus all other CVEs
30-day change
0.00 pp
From 1.04% on 19-09-2026
19-09-202619-10-2026
EPSS score1.04%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Zyxel2 products
- nbg6604_firmware< 1.00\(abir.9\)c0
- nbg6604 series firmware1.00(ABIR.8)C0
1 vendor · 2 products