Privileged Telnet access via hardcoded firmware credentials
Published Jun 4, 2021 · Updated Aug 4, 2024
Hardcoded credentials in D-Link DIR-895L firmware 1.21b05 allow remote attackers to obtain privileged Telnet access. The etc/init0.d/S80telnetd.sh startup script exposes the Telnet username and points to etc/config/image_sign, where the shared password is stored in cleartext. Access requires network reachability to the router's Telnet service but no prior authentication; the credentials grant privileged access and expose sensitive firmware data.
Summary
What happened
Hardcoded credentials in D-Link DIR-895L firmware 1.21b05 allow remote attackers to obtain privileged Telnet access. The etc/init0.d/S80telnetd.sh startup script exposes the Telnet username and points to etc/config/image_sign, where the shared password is stored in cleartext. Access requires network reachability to the router's Telnet service but no prior authentication; the credentials grant privileged access and expose sensitive firmware data.
The record
- CVE
- CVE-2020-29324
- Published
- Jun 4, 2021
- Updated
- Aug 4, 2024
- Vendor
- D-Link
- Product
- DIR-895L
- Classifications
- CWE-312, T1552.001, T1078.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 4, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=v1.21b05
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- DIR-895L Telnet hardcoded-credentials proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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