VDB
KO
HIGH 7.5

GHSA-3244-j874-rhc2

Netty: Memory Exhaustion in RedisArrayAggregator due to Deeply Nested Arrays

Details

### Summary An attacker can cause DoS by sending a crafted Redis payload with deeply nested arrays. This forces the server to allocate a massive number of state objects and collections, leading to memory exhaustion and an OutOfMemoryError.

### Details io.netty.handler.codec.redis.RedisArrayAggregator aggregates RedisMessage parts into ArrayRedisMessage. It uses a `Deque<AggregateState>` to keep track of nested arrays. However, it does not limit the maximum depth of nested arrays. When an attacker sends a continuous stream of nested array headers (e.g., `*1\r\n*1\r\n*1\r\n...`), RedisArrayAggregator pushes a `new AggregateState` onto the stack and allocates a `new ArrayList` for each header. Because there is no depth limit, an attacker can send millions of such headers. This consumes a massive amount of heap memory for the AggregateState instances and their backing ArrayLists, eventually resulting in an OutOfMemoryError.

### Impact Denial of Service due to memory exhaustion. Any application using Netty's RedisArrayAggregator to handle untrusted Redis traffic is vulnerable.

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Affected packages

Maven / io.netty:netty-codec-redis
Introduced in: 4.2.0.Final Fixed in: 4.2.15.Final
Fix # pom.xml: bump <version>4.2.15.Final</version> for io.netty:netty-codec-redis
Maven / io.netty:netty-codec-redis
Introduced in: 0 Fixed in: 4.1.135.Final
Fix # pom.xml: bump <version>4.1.135.Final</version> for io.netty:netty-codec-redis

References