CVE-2017-8335
Public exploit available. Not confirmed exploited in the wild yet. No fix published yet.
What to do
No fixed build or workaround is published yet. Limit exposure and watch for a patch.
What it is
From the CVE record
An issue was discovered on Securifi Almond, Almond+, and Almond 2015 devices with firmware AL-R096. The device provides a user with the capability of setting name for wireless network. These values are stored by the device in NVRAM (Non-volatile RAM). It seems that the POST parameters passed in this request to set up names on the device do not have a string length check on them. This allows an attacker to send a large payload in the "mssid_1" POST parameter. The device also allows a user to view the name of the Wifi Network set by the user. While processing this request, the device calls a function named "getCfgToHTML" at address 0x004268A8 which retrieves the value set earlier by "mssid_1" parameter as SSID2 and this value then results in overflowing the stack set up for this function and allows an attacker to control $ra register value on the stack which allows an attacker to control the device by executing a payload of an attacker's choice. If the firmware version AL-R096 is dissected using binwalk tool, we obtain a cpio-root archive which contains the filesystem set up on the device that contains all the binaries. The binary "goahead" is the one that has the vulnerable function that recieves the values sent by the POST request. If we open this binary in IDA-pro we will notice that this follows a MIPS little endian format. The function sub_00420F38 in IDA pro is identified to be receiving the values sent in the POST parameter "mssid_1" at address 0x0042BA00 and then sets in the NVRAM at address 0x0042C314. The value is later retrieved in the function "getCfgToHTML" at address 0x00426924 and this results in overflowing the buffer due to "strcat" function that is utilized by this function.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
2 sources with a proof of concept or module.
Exploit links, PoCs and Metasploit modules after sign-in- EPSS
2.1% chance of exploitation activity in the next 30 days, which ranks it in the 81st percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
5 events over 2453 days, from the signal feeds we watch.
- Public exploit / PoCsource: github-poc
- Record updated
- Publishedweakness classified, att&ck mapped
Affected products
Technical detail
CVSS 3.0 vector
Open in the CVSS calculatorCVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Scored 8.0 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction RequiredA user must click a link, open a file, or perform some action
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
- Initial AccessT1190Exploit Public-Facing Applicationhigh confidence
- Privilege EscalationT1068Exploitation for Privilege Escalationhigh confidence
Sources
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We'll flag the next CVE, public exploit or patch for Almond 2015 Firmware, not every advisory. This one: public exploit.
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