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Search Results (26 CVEs found)
| CVE | Vendors | Products | Updated | CVSS v3.1 |
|---|---|---|---|---|
| CVE-2026-47271 | 1 Mcdope | 1 Pam Usb | 2026-05-29 | 5.1 Medium |
| pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, src/mem.c implemented out-of-memory guards for xmalloc(), xrealloc(), and xstrdup() using assert(data != NULL). The C standard specifies that all assert() expressions are compiled out when NDEBUG is defined at build time. NDEBUG is commonly defined in release and packaging builds (Debian, Fedora, Arch package flags all define it via -DNDEBUG in CFLAGS). With the guard removed, xmalloc/xrealloc/xstrdup silently return NULL on allocation failure. Every caller in the codebase dereferences the return value without a NULL check -- this is the intended design, as the guard was supposed to abort before the dereference. With the guard gone, any allocation failure causes a NULL pointer dereference, crashing the PAM module. A crash in a PAM module loaded by sudo or login causes authentication to fail for the duration of the crash, creating a local denial-of-service condition. An attacker who can induce memory pressure at authentication time can lock all users out of sudo and login. This vulnerability is fixed in 0.9.0. | ||||
| CVE-2026-47270 | 1 Mcdope | 1 Pam Usb | 2026-05-29 | 6.3 Medium |
| pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, pam_usb is a PAM module loaded into the host process (sudo, login, GDM, GNOME Shell). Display managers such as GDM run multiple concurrent authentication threads. Three functions used by the deny_remote feature called the non-reentrant strtok(), which stores state in a single global pointer. If two authentications race, one thread's strtok() call can overwrite the other's in-progress tokenisation pointer, causing incorrect parsing of the tmux session data or the /proc environ scan that backs the remote-session detection logic. Additionally, pusb_tmux_get_client_tty() passed the raw pointer returned by getenv(TMUX) directly to strtok(). getenv() returns a pointer into the live process environment block; strtok() inserts NUL bytes into that block, permanently corrupting the TMUX variable for subsequent code running in the same process. In long-lived display managers this affects all future authentications in that process. The combined effect can cause deny_remote=true to return an incorrect decision for a remote session, or an incorrect decision for a local session, depending on thread interleaving. This vulnerability is fixed in 0.9.0. | ||||
| CVE-2026-47269 | 1 Mcdope | 1 Pam Usb | 2026-05-29 | 7.4 High |
| pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, pam_usb's deny_remote feature checks utmpx ut_addr_v6 to detect whether an authentication request originates from a remote session. The outer guard was if (utent->ut_addr_v6[0] != 0), which only tests the first 32-bit word of the 128-bit address field. IPv4-mapped IPv6 addresses (::ffff:x.x.x.x) store the IPv4 address in ut_addr_v6[3] with ut_addr_v6[0] == 0. On systems where the SSH daemon listens on :: (IPv6 wildcard) with AddressFamily any -- common on Ubuntu and Debian -- incoming IPv4 connections are recorded in utmpx as IPv4-mapped IPv6 addresses. The outer check evaluates to false, the remote-detection block is skipped entirely, and the session is treated as local. deny_remote=true does not block the authentication. An attacker with physical access to a registered USB device can authenticate over SSH on an affected system as if they were sitting at a local terminal, bypassing the deny_remote restriction. This vulnerability is fixed in 0.9.0. | ||||
| CVE-2026-44711 | 1 Mcdope | 1 Pam Usb | 2026-05-29 | 7.9 High |
| pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, symlink attacks on pad directory and pad files enable authentication bypass and root file corruption. This vulnerability is fixed in 0.8.7. | ||||
| CVE-2026-44710 | 1 Mcdope | 1 Pam Usb | 2026-05-29 | 4.6 Medium |
| pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, src/device.c passed the return values of udisks_drive_get_serial(), udisks_drive_get_vendor(), and udisks_drive_get_model() directly to strcmp() without NULL checks. The GIO/UDisks API documentation states these accessors can return NULL for devices that do not expose the corresponding field. Passing NULL to strcmp() is undefined behaviour (typically a SIGSEGV). This vulnerability is fixed in 0.8.7. | ||||
| CVE-2026-44712 | 1 Mcdope | 1 Pam Usb | 2026-05-29 | 8.2 High |
| pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.8.7, a crafted UUID such as $(id>/tmp/rce) in the config causes root RCE when pamusb-conf --reset-pads is run. A USB device with a crafted filesystem UUID (some controllers allow this) can inject the payload at --add-device time. Also, userName from the XML config is passed to os.system() in pamusb-agent, which invokes a shell. This vulnerability is fixed in 0.8.7. | ||||