CVE-2020-11612 — The ZlibDecoders in Netty 4
The ZlibDecoders in Netty 4.1.x before 4.1.46 allow for unbounded memory allocation while decoding a ZlibEncoded byte stream. An attacker could send a large ZlibEncoded byte stream to the Netty server, forcing the server to allocate all of its free memory to a single decoder.
Published
2020-04-07T18:00:34.000Z
Last modified
2024-08-04T11:35:13.236Z
01What is this vulnerability?
The ZlibDecoders in Netty 4.1.x before 4.1.46 allow for unbounded memory allocation while decoding a ZlibEncoded byte stream. An attacker could send a large ZlibEncoded byte stream to the Netty server, forcing the server to allocate all of its free memory to a single decoder.
02Affected products
| Vendor | Product | Versions |
|---|
| n | a / n/a | n/a |
03Active exploitation status
Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.
07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2020-04-07T18:00:34.000Z
- Last modified: 2024-08-04T11:35:13.236Z
09References
- lists.apache.org — https://lists.apache.org/thread.html/r2958e4d49ee046e1e561e44fdc114a0d2285927501…
- lists.apache.org — https://lists.apache.org/thread.html/r3195127e46c87a680b5d1d3733470f83b886bfd3b8…
- lists.apache.org — https://lists.apache.org/thread.html/r14446ed58208cb6d97b6faa6ebf145f1cf2c70c088…
- lists.apache.org — https://lists.apache.org/thread.html/ra98e3a8541a09271f96478d5e22c7e3bd1afdf4864…
- lists.apache.org — https://lists.apache.org/thread.html/r8a654f11e1172b0effbfd6f8d5b6ca651ae4ac724a…
- lists.apache.org — https://lists.apache.org/thread.html/r7836bbdbe95c99d4d725199f0c169927d4e87ba57e…
- lists.apache.org — https://lists.apache.org/thread.html/r5b1ad61552591b747cd31b3a908d5ff2e8f2a8a684…
- lists.apache.org — https://lists.apache.org/thread.html/r88e2b91560c065ed67e62adf8f401c417e4d70256d…
- lists.apache.org — https://lists.apache.org/thread.html/rfd173eac20d5e5f581c8984b685c836dafea8eb2f7…
- lists.apache.org — https://lists.apache.org/thread.html/ref2c8a0cbb3b8271e5b9a06457ba78ad2028128627…
- lists.apache.org — https://lists.apache.org/thread.html/r255ed239e65d0596812362adc474bee96caf7ba042…
- lists.apache.org — https://lists.apache.org/thread.html/rf803b65b4a57589d79cf2e83d8ece0539018d32864…
- lists.apache.org — https://lists.apache.org/thread.html/rd302ddb501fa02c5119120e5fc21df9a1c00e221c4…
- lists.apache.org — https://lists.apache.org/thread.html/re1ea144e91f03175d661b2d3e97c7d74b912e01961…
- lists.apache.org — https://lists.apache.org/thread.html/r866288c2ada00ce148b7307cdf869f15f24302b3eb…
- lists.apache.org — https://lists.apache.org/thread.html/rff8859c0d06b1688344b39097f9685c43b461cf2bc…
- lists.apache.org — https://lists.apache.org/thread.html/r4a7e4e23bd84ac24abf30ab5d5edf989c02b555e1e…
- lists.apache.org — https://lists.apache.org/thread.html/r9c30b7fca4baedebcb46d6e0f90071b30cc4a0e074…
- lists.apache.org — https://lists.apache.org/thread.html/r281882fdf9ea89aac02fd2f92786693a956aac2ce9…
- lists.apache.org — https://lists.apache.org/thread.html/r5030cd8ea5df1e64cf6a7b633eff145992fbca03e8…
- lists.apache.org — https://lists.apache.org/thread.html/r3ea4918d20d0c1fa26cac74cc7cda001d8990bc434…
- lists.apache.org — https://lists.apache.org/thread.html/ref3943adbc3a8813aee0e3a9dd919bacbb27f626be…
- lists.apache.org — https://lists.apache.org/thread.html/r9addb580456807cd11d6f0c6b6373b7d7161d06d22…
- lists.apache.org — https://lists.apache.org/thread.html/r4f4a14d6a608db447b725ec2e96c26ac9664d83cd8…
- lists.apache.org — https://lists.apache.org/thread.html/r7641ee788e1eb1be4bb206a7d15f8a64ec6ef23e5e…
- lists.apache.org — https://lists.apache.org/thread.html/rf9f8bcc4ca8d2788f77455ff594468404732a4497b…
- lists.apache.org — https://lists.apache.org/thread.html/r5a0b1f0b1c3bcd66f5177fbd6f6de2d0f8cae24a13…
- lists.apache.org — https://lists.apache.org/thread.html/r69b23a94d4ae45394cabae012dd1f4a963996869c4…
- lists.debian.org — https://lists.debian.org/debian-lts-announce/2020/09/msg00003.html
- lists.apache.org — https://lists.apache.org/thread.html/raaac04b7567c554786132144bea3dcb72568edd410…
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