CVE-2020-36443
Use of Uninitialized Resource in libp2p-deflate
An issue was discovered in the libp2p-deflate crate before 0.27.1 for Rust. An uninitialized buffer is passed to AsyncRead::poll_read(), which is a user-provided trait function.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in the libp2p-deflate crate before 0.27.1 for Rust. An uninitialized buffer is passed to AsyncRead::poll_read(), which is a user-provided trait function.
- Record
CVE-2020-36443- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-908
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in the libp2p-deflate crate before 0.27.1 for Rust. An uninitialized buffer is passed to AsyncRead::poll_read(), which is a user-provided trait function.
- Record
CVE-2020-36443- Updated
- 2026-11-02
EUVDEUVD-2021-1730 No score
An issue was discovered in the libp2p-deflate crate before 0.27.1 for Rust. An uninitialized buffer is passed to AsyncRead::poll_read(), which is a user-provided trait function.
- Record
EUVD-2021-1730- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gvcp-948f-8f2p
Use of Uninitialized Resource in libp2p-deflate
An issue was discovered in the libp2p-deflate crate before 0.27.1 for Rust. An uninitialized buffer is passed to AsyncRead::poll_read(), which is a user-provided trait function.
- Record
GHSA-gvcp-948f-8f2p- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-908
- Updated
- 2026-11-02
OSVGHSA-gvcp-948f-8f2p
Use of Uninitialized Resource in libp2p-deflate
An issue was discovered in the libp2p-deflate crate before 0.27.1 for Rust. An uninitialized buffer is passed to AsyncRead::poll_read(), which is a user-provided trait function.
- Record
GHSA-gvcp-948f-8f2p- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-908
- Updated
- 2026-11-02
OSVRUSTSEC-2020-0123
Contents of uninitialized memory exposed in DeflateOutput's AsyncRead implementation
Affected versions of this crate passes an uninitialized buffer to a user-provided trait function AsyncRead::poll_read().
Arbitrary AsyncRead::poll_read() implementations can read from the uninitialized buffer (memory exposure) and also can return incorrect number of bytes written to the buffer.
Reading from uninitialized memory produces undefined values that can quickly invoke undefined behavior.
The flaw was fixed in commit 5ba266a by ensuring the newly allocated part of the buffer is zero-initialized before passing it to a user-provided AsyncRead::poll_read().
- Record
RUSTSEC-2020-0123- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libp2p-deflatecrates.io |
before 0.27.1 | 0.27.1 |
libp2p-deflatecrates.io |
0.0.0-0 up to 0.27.1 | 0.27.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-36443 is a critical vulnerability (CVSS 9.8) in Libp2p Libp2p-deflate, published January 24, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.23%, the 69th percentile. Fixed in libp2p-deflate 0.27.1.
References
rustsec.org/advisories/RUSTSEC-2020-0123.html
raw.githubusercontent.com/rustsec/advisory-db/main/crates/libp2p-deflate/RUSTSEC-2020-0123.md
nvd.nist.gov/vuln/detail/CVE-2020-36443
github.com/advisories/GHSA-gvcp-948f-8f2p
crates.io/crates/libp2p-deflate