CVE-2021-23242
CVE-2021-23242 is a medium-severity vulnerability in Mercusys Mercury X18g Firmware with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-22.
Key facts
- Severity: Medium (CVSS 3.x base score 5.3)
- CVSS v2: 5.0
- EPSS exploit prediction: 2% (76th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-22
- Affected product: Mercusys Mercury X18g Firmware
- Published:
- Last modified:
Description
MERCUSYS Mercury X18G 1.0.5 devices allow Directory Traversal via ../ to the UPnP server, as demonstrated by the /../../conf/template/uhttpd.json URI.
Frequently asked questions
- What is CVE-2021-23242?
- MERCUSYS Mercury X18G 1.0.5 devices allow Directory Traversal via ../ to the UPnP server, as demonstrated by the /../../conf/template/uhttpd.json URI.
- How severe is CVE-2021-23242?
- CVE-2021-23242 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
- Is CVE-2021-23242 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-23242?
- CVE-2021-23242 affects Mercusys Mercury X18g Firmware. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-23242?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2021-23242 published?
- CVE-2021-23242 was published on 2021-01-07 and last updated on 2026-06-17.
References
- https://github.com/BATTZION/MY_REQUEST/blob/master/Mercury%20Router%20Upnp%20Server%20Directory%20Traversal.md
- https://www.mercurycom.com.cn/product-521-1.html
- https://www.mercusys.com/en/
Affected products (1)
- cpe:2.3:o:mercusys:mercury_x18g_firmware:1.0.5:*:*:*:*:*:*:*
More vulnerabilities in Mercusys Mercury X18g Firmware
- CVE-2021-25811 — High (CVSS 7.5): MERCUSYS Mercury X18G 1.0.5 devices allow Denial of service via a crafted value to the POST listen_http_lan parameter.…
- CVE-2021-25810 — Medium (CVSS 6.1): Cross site Scripting (XSS) vulnerability in MERCUSYS Mercury X18G 1.0.5 devices, via crafted values to the…
- CVE-2021-23241 — Medium (CVSS 5.3): MERCUSYS Mercury X18G 1.0.5 devices allow Directory Traversal via ../ in conjunction with a loginLess or login.htm URI…
All CVEs affecting Mercusys Mercury X18g Firmware →
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