CVE-2021-20277 Memory corruption in samba
High 7.5
Published
Updated
Check this codebase for CVE-2021-20277 and fix it if it is affected.
What it is: CVE-2021-20277 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 12 May 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-2021-20277 in the wild and no public exploit code.
Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.
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-2021-20277/ (Markdown: https://insights.sbomify.com/CVE-2021-20277/index.md)
An out-of-bounds memory write in Samba's libldb allows attackers to crash the LDAP server, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-20277?
CVE-2021-20277 is a high-severity memory corruption vulnerability in Debian Debian Linux, published on 12 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A flaw was found in Samba's libldb. Multiple, consecutive leading spaces in an LDAP attribute can lead to an out-of-bounds memory write, leading to a crash of the LDAP server process handling the request. The highest threat from this vulnerability is to system availability.
Which versions are affected by CVE-2021-20277?
It affects 3 products.
Linux distribution packages (40)
ldb-tools Red Hat:enterprise_linux:7::client | All versions | 0:1.5.4-2.el7_9 |
libldb Red Hat:enterprise_linux:7::client | All versions | 0:1.5.4-2.el7_9 |
libldb-debuginfo Red Hat:enterprise_linux:7::client | All versions | 0:1.5.4-2.el7_9 |
libldb-devel Red Hat:enterprise_linux:7::client | All versions | 0:1.5.4-2.el7_9 |
pyldb Red Hat:enterprise_linux:7::client | All versions | 0:1.5.4-2.el7_9 |
pyldb-devel Red Hat:enterprise_linux:7::client | All versions | 0:1.5.4-2.el7_9 |
ldb-tools Red Hat:enterprise_linux:7::computenode | All versions | 0:1.5.4-2.el7_9 |
libldb-debuginfo Red Hat:enterprise_linux:7::computenode | All versions | 0:1.5.4-2.el7_9 |
libldb-devel Red Hat:enterprise_linux:7::computenode | All versions | 0:1.5.4-2.el7_9 |
pyldb-devel Red Hat:enterprise_linux:7::computenode | All versions | 0:1.5.4-2.el7_9 |
ldb-tools Red Hat:enterprise_linux:7::server | All versions | 0:1.5.4-2.el7_9 |
libldb Red Hat:enterprise_linux:7::server | All versions | 0:1.5.4-2.el7_9 |
libldb-debuginfo Red Hat:enterprise_linux:7::server | All versions | 0:1.5.4-2.el7_9 |
libldb-devel Red Hat:enterprise_linux:7::server | All versions | 0:1.5.4-2.el7_9 |
pyldb Red Hat:enterprise_linux:7::server | All versions | 0:1.5.4-2.el7_9 |
pyldb-devel Red Hat:enterprise_linux:7::server | All versions | 0:1.5.4-2.el7_9 |
ldb-tools Red Hat:enterprise_linux:7::workstation | All versions | 0:1.5.4-2.el7_9 |
libldb Red Hat:enterprise_linux:7::workstation | All versions | 0:1.5.4-2.el7_9 |
libldb-debuginfo Red Hat:enterprise_linux:7::workstation | All versions | 0:1.5.4-2.el7_9 |
libldb-devel Red Hat:enterprise_linux:7::workstation | All versions | 0:1.5.4-2.el7_9 |
pyldb Red Hat:enterprise_linux:7::workstation | All versions | 0:1.5.4-2.el7_9 |
pyldb-devel Red Hat:enterprise_linux:7::workstation | All versions | 0:1.5.4-2.el7_9 |
ldb-tools Red Hat:enterprise_linux:8::baseos | All versions | 0:2.1.3-3.el8_3 |
ldb-tools-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 0:2.1.3-3.el8_3 |
libldb Red Hat:enterprise_linux:8::baseos | All versions | 0:2.1.3-3.el8_3 |
libldb-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 0:2.1.3-3.el8_3 |
libldb-debugsource Red Hat:enterprise_linux:8::baseos | All versions | 0:2.1.3-3.el8_3 |
libldb-devel Red Hat:enterprise_linux:8::baseos | All versions | 0:2.1.3-3.el8_3 |
python3-ldb Red Hat:enterprise_linux:8::baseos | All versions | 0:2.1.3-3.el8_3 |
python3-ldb-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 0:2.1.3-3.el8_3 |
ldb-tools Red Hat:rhel_aus:7.6::server | All versions | 0:1.3.4-2.el7_6 |
libldb Red Hat:rhel_aus:7.6::server | All versions | 0:1.3.4-2.el7_6 |
libldb-debuginfo Red Hat:rhel_aus:7.6::server | All versions | 0:1.3.4-2.el7_6 |
libldb-devel Red Hat:rhel_aus:7.6::server | All versions | 0:1.3.4-2.el7_6 |
pyldb Red Hat:rhel_aus:7.6::server | All versions | 0:1.3.4-2.el7_6 |
pyldb-devel Red Hat:rhel_aus:7.6::server | All versions | 0:1.3.4-2.el7_6 |
ldb-tools Red Hat:rhel_e4s:7.6::server | All versions | 0:1.3.4-2.el7_6 |
libldb Red Hat:rhel_e4s:7.6::server | All versions | 0:1.3.4-2.el7_6 |
libldb-debuginfo Red Hat:rhel_e4s:7.6::server | All versions | 0:1.3.4-2.el7_6 |
libldb-devel Red Hat:rhel_e4s:7.6::server | All versions | 0:1.3.4-2.el7_6 |
Products include Debian Debian Linux, Fedoraproject Fedora, Samba Samba.
How do I fix CVE-2021-20277?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-20277 being exploited?
There is no known exploitation of CVE-2021-20277 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALPINE-CVE-2021-20277, AZL-37000, AZL-44535, AZL-7353, DEBIAN-CVE-2021-20277, ECHO-51a5-064b-0e9b and 8 more.