CVE-2023-25752

What it actually does

Missing bounds check on available byte counts when accessing throttled streams allows calling functions to operate on incorrect values, potentially enabling future code to make invalid assumptions.

Why it matters to the business

Attackers may corrupt data processed by the application, leading to integrity failures in browser or related tooling without affecting confidentiality or availability.

How an attack unfolds

An attacker supplies a throttled stream response with a byte count that exceeds actual available data; the missing validation in the caller permits subsequent operations to act on out-of-bounds or fabricated values, resulting in manipulated data processing.

How to fix it

Update Firefox to 111 or newer, Firefox ESR to 102.9 or newer, Thunderbird to 102.9 or newer; for rust-lang/cargo update to commit 9835622853f08be9a4b58ebe29dcec8f43b64b33.

How to confirm the fix worked

Confirm installed versions meet or exceed the listed fixed releases and exercise throttled stream handling to ensure byte-count validation occurs.

Typical attack path

1. Serve malicious or crafted throttled stream content to the victim
2. Trigger stream access in the affected code path
3. Rely on unchecked byte count to induce incorrect data handling

How to detect it

Inspect browser or cargo process logs for anomalous byte-count values or stream-handling errors around the time of suspected activity; correlate with network captures showing throttled responses.

What your security team should do

• Apply the listed version or commit updates immediately given the integrity impact
• Audit any downstream code that consumes throttled streams for similar assumptions
• Include stream-related test cases in regression suites after patching