Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-12503— Loytec LINX firmware: Improper Link Resolution in /usr/bin/larm_starter

Quick assessment

Affected
Loytec LIP-ME20xC
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

LOYTEC LIP-ME20xC是LOYTEC公司的一款工业路由器。 LOYTEC L-INX 8.4.16及之前版本、L-GATE 8.4.16及之前版本、L-ROC 8.4.16及之前版本、L-IOB 8.4.16及之前版本、L-DALI 8.4.16及之前版本、L-VIS 8.4.16及之前版本和L-PAD 8.4.16及之前版本存在后置链接漏洞，该漏洞源于/usr/bin/larm_starter中存在不当链接解析，可能导致经过身份验证的攻击者通过符号链接攻击/etc/lighttpd/ssl/

CVSS 9.2 · Critical EPSS 0.18% · P8

Possible ATT&CK Techniques 1 AI

T1546.001 · Change Default File Association

Affected Version Matrix 8

VendorProduct Version RangeStatus
Loytec L-DALI ≤ 8.4.16 affected
Loytec L-GATE ≤ 8.4.16 affected
Loytec L-INX ≤ 8.4.16 affected
Loytec L-IOB ≤ 8.4.16 affected
Loytec L-PAD ≤ 8.4.16 affected
Loytec L-ROC ≤ 8.4.16 affected
Loytec L-VIS ≤ 8.4.16 affected
Loytec LIP-ME20xC ≤ 8.4.16 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-12503

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Loytec LINX firmware: Improper Link Resolution in /usr/bin/larm_starter
Source: CVE Program / CVE List V5
Vulnerability Description
Improper Link Resolution (CWE-59) in `/usr/bin/larm_starter` in Loytec L-INX, L-GATE, L-ROC, L-IOB, L-DALI, L-VIS and L-PAD through 8.4.16 on LINX-A64 allows an authenticated `larmapp` attacker to make `/etc/passwd` writable by the `larmapp` group (leading to root privilege escalation) via a symlink attack on `/etc/lighttpd/ssl/server.pem`.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:H/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
在文件访问前对链接解析不恰当(链接跟随)
Source: CVE Program / CVE List V5
Vulnerability Title
LOYTEC LIP-ME20xC 后置链接漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
LOYTEC LIP-ME20xC是LOYTEC公司的一款工业路由器。 LOYTEC L-INX 8.4.16及之前版本、L-GATE 8.4.16及之前版本、L-ROC 8.4.16及之前版本、L-IOB 8.4.16及之前版本、L-DALI 8.4.16及之前版本、L-VIS 8.4.16及之前版本和L-PAD 8.4.16及之前版本存在后置链接漏洞，该漏洞源于/usr/bin/larm_starter中存在不当链接解析，可能导致经过身份验证的攻击者通过符号链接攻击/etc/lighttpd/ssl/
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Loytec LIP-ME20xC 0 ~ 8.4.16 -
Loytec L-INX 0 ~ 8.4.16 -
Loytec L-GATE 0 ~ 8.4.16 -
Loytec L-ROC 0 ~ 8.4.16 -
Loytec L-IOB 0 ~ 8.4.16 -
Loytec L-DALI 0 ~ 8.4.16 -
Loytec L-VIS 0 ~ 8.4.16 -
Loytec L-PAD 0 ~ 8.4.16 -

II. Public POCs for CVE-2026-12503

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-12503

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-12503 (1)

Same Patch Batch · Loytec · 2026-07-24 · 9 CVEs total

CVE-2026-12496 8.7 HIGH Loytec LINX firmware: Unauthenticated stored XSS in OPC XML-DA server
CVE-2026-55730 8.7 HIGH Loytec LWEB802: Reflected Cross-Site Scripting in LWEB802
CVE-2026-55732 8.7 HIGH Loytec LINX firmware: Out-of-bounds Read in BACnet packet parsing (bacdt_datetime_to_tod)
CVE-2026-12502 8.4 HIGH Loytec LINX firmware: Improper Privilege Management in /usr/bin/ltsudo
CVE-2026-12504 8.4 HIGH Loytec LINX firmware: Improper Authentication in PAM configuration
CVE-2026-55729 7.7 HIGH Loytec LWEB802: Exposure of Sensitive Information in browser localStorage
CVE-2026-55731 6.6 MEDIUM Loytec LINX firmware: Unchecked input for loop condition in the SNMP agent
CVE-2026-55728 3.8 LOW Loytec LINX firmware: Stack-based Buffer Overflow in cmd_ipaddr_conflict

IV. Related Vulnerabilities

Same product: LIP-ME20xC
Same vendor: Loytec
Same weakness: CWE-59