Out-of-bounds read in FFmpeg 8.0 and 8.0.1 RV60 video decoder (libavcodec/rv60dec.c). The quantization parameter (qp) validation at line 2267 only checks the lower bound (qp < 0) but is missing upper bound validation. The qp value can reach 65 (base value 63 from 6-bit frame header + offset +2 from read_qp_offset) while the rv60_qp_to_idx array has size 64 (valid indices 0-63). This results in out-of-bounds array access at lines 1554 (decode_cbp8), 1655 (decode_cbp16), and 1419/1421 (get_c4x4_set), potentially leading to memory disclosure or crash. A previous fix in commit 61cbcaf93f added validation only for intra frames. This vulnerability affects the released versions 8.0 (released 2025-08-22) and 8.0.1 (released 2025-11-20) and is fixed in git master commit 8abeb879df which will be included in FFmpeg 8.1.
Weakness
The product reads data past the end, or before the beginning, of the intended buffer.
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.