CVE-2026-64445

In the Linux kernel, the following vulnerability has been resolved:

staging: rtl8723bs: fix WEP length underflow and OOB read in OnAuth()

OnAuth() has two bugs in the shared-key authentication path.

When the Privacy bit is set, rtw_wep_decrypt() is called without verifying that the frame is long enough to contain a valid WEP IV and ICV. Inside rtw_wep_decrypt(), length is computed as:

length = len - WLAN_HDR_A3_LEN - iv_len

and then passed as (length - 4) to crc32_le(). If len is less than WLAN_HDR_A3_LEN + iv_len + icv_len (32 bytes), length - 4 is negative and, after the implicit cast to size_t, causes crc32_le() to read far beyond the frame buffer. Add a minimum length check before accessing the IV field and calling the decryption path.

When processing a seq=3 response, rtw_get_ie() stores the Challenge Text IE length in ie_len, but the subsequent memcmp() always reads 128 bytes regardless of ie_len. IEEE 802.11 mandates a challenge text of exactly 128 bytes; reject any IE whose length field differs, matching the check already applied to OnAuthClient().

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/1f6c9d255bdda41216b6e34c96aa2b1abee0bb84
• https://git.kernel.org/stable/c/3e44a7665f3abd320a80d9c64ee4a93317041b8b
• https://git.kernel.org/stable/c/64ec4192d9c10e96922245d4a6747304cc76b19d
• https://git.kernel.org/stable/c/665e1ecb68b4e8419604e70a33f02d1c8b0222c6
• https://git.kernel.org/stable/c/87cccc2a767f17dcab71e3b9fe5ae29b5516c5ce
• https://git.kernel.org/stable/c/a1fc19d61f661d47204f095b593de507884849f7
• https://git.kernel.org/stable/c/c9000c93078e5c0a5a651b077c0ec92a4bc7d580
• https://git.kernel.org/stable/c/d90b9f39f375c9826ef145605dfe97765d0ecb91