Security readout for executives and security teams
Plain-English summary
CVE-2011-4126 is a local race condition in Calibre's Linux mount helper. The bundle says an unprivileged user could mount any device anywhere, which can cross expected system boundaries. Exposure is mainly on Linux systems where vulnerable Calibre versions installed this helper.
Executive priority
Treat this as a targeted local-risk cleanup item, not an internet-wide emergency. Prioritize shared Linux workstations, build hosts, and multi-user systems where unprivileged users exist.
Technical view
The reported flaw is CWE-367, a time-of-check/time-of-use race in devices/linux_mount_helper.c. The stated impact is that unprivileged users could direct mounts broadly rather than being constrained. Affected Calibre versions are not identified in the bundle.
Likely exposure
Linux endpoints or servers with Calibre installed and the vulnerable linux_mount_helper present. The bundle does not name exact vulnerable or fixed versions, package builds, or distributions.
Exploitation context
KEV is false. The bundle references public discussion, a Launchpad bug, LWN coverage, and an exploit-focused repository, but it does not prove active exploitation in the wild.
Researcher notes
Evidence supports a local TOCTOU issue in Calibre's mount helper, but version boundaries and official remediation details are incomplete in the supplied bundle. Avoid assuming exploitability beyond local unprivileged access unless vendor or distribution advisories add detail.
Mitigation direction
- Check Calibre vendor and distribution advisories for fixed package versions.
- Upgrade Calibre from trusted package sources where a fix is available.
- Remove Calibre or its mount helper where not operationally required.
- Restrict local shell access on systems carrying vulnerable Calibre installations.
- Track affected Linux hosts until version status is confirmed.
Validation and detection
- Inventory Linux systems for installed Calibre packages.
- Confirm whether devices/linux_mount_helper exists on those systems.
- Compare installed versions against vendor or distribution advisory status.
- Review local file permissions and ownership for the mount helper.
- Check vulnerability scanners for CVE-2011-4126 coverage and results.
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-367: 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 lookupCVE-2011-4126 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.zx2c4.com/calibre-mount-helper-exploit/about/CVE reference · x_refsource_MISC
- https://www.openwall.com/lists/oss-security/2011/11/02/2CVE reference · x_refsource_MISC
- https://bugs.launchpad.net/calibre/+bug/885027CVE reference · x_refsource_MISC
- https://lwn.net/Articles/464824/CVE 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.
Time-of-check Time-of-use (TOCTOU) Race Condition
Time-of-check Time-of-use (TOCTOU) Race Condition represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.