A stack buffer overflow vulnerability exists in the D-Link DIR-816A2 router firmware DIR-816A2_FWv1.10CNB05_R1B011D88210.img in the upload.cgi module, which handles firmware version information. The vulnerability occurs because /proc/version is read into a 512-byte buffer and then concatenated using sprintf() into another 512-byte buffer containing a 29-byte constant. Input exceeding 481 bytes triggers a stack buffer overflow, allowing an attacker who can control /proc/version content to potentially execute arbitrary code on the device.

An unauthenticated command injection vulnerability exists in the D-Link DIR-878A1 router firmware FW101B04.bin. The vulnerability occurs in the 'SetDynamicDNSSettings' functionality, where the 'ServerAddress' and 'Hostname' parameters in prog.cgi are stored in NVRAM and later used by rc to construct system commands executed via twsystem(). An attacker can exploit this vulnerability remotely without authentication by sending a specially crafted HTTP request, leading to arbitrary command execution on the device.

A command injection vulnerability exists in the D-Link DIR-823G router firmware DIR823G_V1.0.2B05_20181207.bin in the timelycheck and sysconf binaries, which process the /var/system/linux_vlan_reinit file. The vulnerability occurs because content read from this file is only partially validated for a prefix and then formatted using vsnprintf() before being executed with system(), allowing an attacker with write access to /var/system/linux_vlan_reinit to execute arbitrary commands on the device.

A stack-based buffer overflow exists in the get_merge_mac function of the httpd binary on Linksys E1200 v2 routers (Firmware E1200_v2.0.11.001_us.tar.gz). The function concatenates up to six user-supplied CGI parameters matching <parameter>_0~5 into a fixed-size buffer (a2) without proper bounds checking, appending colon delimiters during concatenation. Remote attackers can exploit this vulnerability via specially crafted HTTP requests to execute arbitrary code or cause denial of service without authentication.

A command injection vulnerability exists in the D-Link DIR-882 Router firmware DIR882A1_FW102B02 within the `prog.cgi` and `rc` binaries. The `sub_4438A4` function in `prog.cgi` stores user-supplied DDNS parameters (`ServerAddress` and `Hostname`) in NVRAM via `nvram_safe_set`. These values are later retrieved in the `start_DDNS_ipv4` function of `rc` using `nvram_safe_get` and concatenated into DDNS shell commands executed via `twsystem()` without proper sanitization. Partial string comparison is performed but is insufficient to prevent command injection. An unauthenticated remote attacker can exploit this vulnerability to execute arbitrary commands on the device through specially crafted HTTP requests to the router's web interface.

A command injection vulnerability exists in the D-Link DIR-882 Router firmware DIR882A1_FW102B02 within the `prog.cgi` and `rc` binaries. The `sub_433188` function in `prog.cgi` stores user-supplied email configuration parameters (`EmailFrom`, `EmailTo`, `SMTPServerAddress`, `SMTPServerPort`, `AccountName`) in NVRAM via `nvram_safe_set`. These values are later retrieved in the `sub_448FDC` function of `rc` using `nvram_safe_get` and concatenated into shell commands executed via `twsystem()` without sanitization. An unauthenticated remote attacker can exploit this vulnerability to execute arbitrary commands on the device through specially crafted HTTP requests to the router's web interface.

A command injection vulnerability exists in the D-Link DIR-882 Router firmware DIR882A1_FW102B02 within the `prog.cgi` and `librcm.so` binaries. The `sub_4455BC` function in `prog.cgi` stores user-supplied `SetDMZSettings/IPAddress` values in NVRAM via `nvram_safe_set("dmz_ipaddr", ...)`. These values are later retrieved in the `DMZ_run` function of `librcm.so` using `nvram_safe_get` and concatenated into `iptables` shell commands executed via `twsystem()` without any sanitization. An unauthenticated remote attacker can exploit this vulnerability to execute arbitrary commands on the device through specially crafted HTTP requests to the router's web interface.

A command injection vulnerability exists in the D-Link DIR-882 Router firmware DIR882A1_FW102B02 within the `prog.cgi` and `rc` binaries. The `sub_432F60` function in `prog.cgi` stores user-supplied `SetSysLogSettings/IPAddress` values in NVRAM via `nvram_safe_set("SysLogRemote_IPAddress", ...)`. These values are later retrieved in the `sub_448DCC` function of `rc` using `nvram_safe_get` and concatenated into a shell command executed via `twsystem()` without any sanitization. An unauthenticated remote attacker can exploit this vulnerability to execute arbitrary commands on the device through specially crafted HTTP requests to the router's web interface.