Security readout for executives and security teams
Plain-English summary
CVE-2021-3710 is a local information disclosure flaw in Ubuntu's Apport crash-reporting tool. A path traversal bug in read_file() could let a low-privileged local user read sensitive information. It does not indicate remote code execution, data tampering, or service outage.
Executive priority
Treat this as a confidentiality risk requiring normal vulnerability-management action, not an emergency internet-wide incident. Patch exposed Ubuntu fleets promptly, with higher priority for shared or regulated environments.
Technical view
The issue is CWE-24 path traversal in apport/hookutils.py read_file(). CVSS 3.1 is 6.5: local access, low complexity, low privileges, no user interaction, changed scope, high confidentiality impact, no integrity or availability impact.
Likely exposure
Exposure is likely limited to Ubuntu systems running affected Apport package versions, especially multi-user servers, developer workstations, and ESM/LTS fleets where untrusted local users may have accounts.
Exploitation context
The provided sources do not cite active exploitation, and KEV status is false. Exploitation requires local low-privileged access and appears focused on unauthorized file disclosure through path traversal, not direct remote compromise.
Researcher notes
Affected versions include Apport 2.14.1, 2.20.1, 2.20.9, and 2.20.11 before specific Ubuntu fixed builds. The record identifies path traversal in read_file(); sources do not provide public exploitation evidence.
Mitigation direction
- Upgrade Apport to the fixed Ubuntu package for each supported release.
- Use Ubuntu USN-5077-1 and USN-5077-2 as the remediation baseline.
- Prioritize systems with shared shell access or untrusted local users.
- If patching is delayed, review Canonical guidance for supported temporary measures.
Validation and detection
- Inventory installed Apport versions across Ubuntu systems.
- Compare versions against the fixed package thresholds listed for CVE-2021-3710.
- Confirm Ubuntu security updates USN-5077-1 or USN-5077-2 are applied where relevant.
- Review local user exposure on systems that cannot be patched promptly.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-24: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-3710 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N24Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://ubuntu.com/security/notices/USN-5077-1CVE reference · x_refsource_MISC
- https://ubuntu.com/security/notices/USN-5077-2CVE reference · x_refsource_MISC
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3710CVE reference · x_refsource_MISC
- https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1933832CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Path Traversal: '../filedir'
Path Traversal: '../filedir' represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.