CVE-2020-25659 RSA decryption vulnerable to Bleichenbacher timing vulnerability
Medium 5.9
Published
Updated
Check this codebase for CVE-2020-25659 and fix it if it is affected.
What it is: CVE-2020-25659 is a medium-severity vulnerability in python-cryptography, published on 11 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-25659 in the wild and no public exploit code.
Affected packages and fixed versions:
- cryptography (PyPI): affected all versions; fixed in 3.2
- cryptography (PyPI): affected all versions; fixed in 3.2
- cryptography (PyPI): affected all versions; fixed in 3.2.1
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2020-25659/ (Markdown: https://insights.sbomify.com/CVE-2020-25659/index.md)
Attackers can exploit timing side-channels in RSA decryption to potentially recover plaintext, affecting applications using the python-cryptography library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-25659?
CVE-2020-25659 is a medium-severity vulnerability in python-cryptography, published on 11 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
python-cryptography 3.2 is vulnerable to Bleichenbacher timing attacks in the RSA decryption API, via timed processing of valid PKCS#1 v1.5 ciphertext.
Weakness: CWE-385
Which versions are affected by CVE-2020-25659?
3 open source packages ship an affected version, including cryptography. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
cryptography PyPI | All versions | 3.2 |
cryptography PyPI | All versions | 3.2 |
cryptography PyPI | All versions | 3.2.1 |
Linux distribution packages (23)
python-cryptography SUSE:Enterprise Storage 5 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:HPE Helion OpenStack 8 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Module for Basesystem 15 SP2 | All versions | 2.8-3.3.1 |
python-cryptography SUSE:Linux Enterprise Module for Basesystem 15 SP4 | All versions | 3.3.2-150400.16.3.1 |
python-cryptography SUSE:Linux Enterprise Module for Python 2 15 SP2 | All versions | 2.8-3.3.1 |
python-cryptography SUSE:Linux Enterprise Server 12 SP2-BCL | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Server 12 SP2-LTSS | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Server 12 SP3-BCL | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Server 12 SP3-LTSS | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Server 12 SP4-LTSS | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Server 12 SP5 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Server for SAP Applications 12 SP2 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Server for SAP Applications 12 SP3 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Server for SAP Applications 12 SP4 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:OpenStack Cloud 7 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:OpenStack Cloud 8 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:OpenStack Cloud 9 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:OpenStack Cloud Crowbar 8 | All versions | 2.1.4-7.31.1 |
python-cryptography SUSE:OpenStack Cloud Crowbar 9 | All versions | 2.1.4-7.31.1 |
python-cryptography openSUSE:Leap 15.2 | All versions | 2.8-lp152.2.3.1 |
python-cryptography openSUSE:Leap 15.4 | All versions | 3.3.2-150400.16.3.1 |
python-cryptography-vectors openSUSE:Leap 15.4 | All versions | 3.3.2-150400.7.3.1 |
Products include Cryptography.io Cryptography, Oracle Communications Cloud Native Core Network Function Cloud Native Environment.
How do I fix CVE-2020-25659?
Upgrade cryptography to a fixed version for your release line: 3.2 or 3.2.1.
Is CVE-2020-25659 being exploited?
There is no known exploitation of CVE-2020-25659 in the wild and no public exploit code.
Other vulnerabilities in python-cryptography
- CVE-2020-36242 PyCA Cryptography symmetrically encrypting large values can lead to integer overflow
- CVE-2026-26007 cryptography Subgroup Attack Due to Missing Subgroup Validation for SECT Curves
- CVE-2024-26130 cryptography NULL pointer dereference with pkcs12.serialize_key_and_certificates when called with a non-matching certificate and private key and an hmac_hash override
- CVE-2023-38325 cryptography mishandles SSH certificates
- CVE-2026-39892 cryptography has a buffer overflow if non-contiguous buffers were passed to APIs
Sources
Also known as ALPINE-CVE-2020-25659, DEBIAN-CVE-2020-25659, GHSA-hggm-jpg3-v476, MGASA-2020-0438, MINI-v93q-6867-pj79, PYSEC-2021-62 and 6 more.