exec: Force single empty string when argv is empty
In the Linux kernel, the following vulnerability has been resolved: exec: Force single empty string when argv is empty Quoting[1] Ariadne Conill: "In several other operating systems, it is a hard requirement that the second argument to execve(2) be the name of a program, thus prohibiting a scenario where argc < 1. POSIX 2017 also recommends this behaviour, but it is not an explicit requirement[2]: The argument arg0 should point to a filename string that is associated with the process being started by one of the exec functions. ... Interestingly, Michael Kerrisk opened an issue about this in 2008[3], but there was no consensus to support fixing this issue then. Hopefully now that CVE-2021-4034 shows practical exploitative use[4] of this bug in a shellcode, we can reconsider. This issue is being tracked in the KSPP issue tracker[5]." While the initial code searches[6][7] turned up what appeared to be mostly corner case tests, trying to that just reject argv == NULL (or an immediately terminated pointer list) quickly started tripping[8] existing userspace programs. The next best approach is forcing a single empty string into argv and adjusting argc to match. The number of programs depending on argc == 0 seems a smaller set than those calling execve with a NULL argv. Account for the additional stack space in bprm_stack_limits(). Inject an empty string when argc == 0 (and set argc = 1). Warn about the case so userspace has some notice about the change: process './argc0' launched './argc0' with NULL argv: empty string added Additionally WARN() and reject NULL argv usage for kernel threads. [1] https://lore.kernel.org/lkml/20220127000724.15106-1-ariadne@dereferenced.org/ [2] https://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html [3] https://bugzilla.kernel.org/show_bug.cgi?id=8408 [4] https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt [5] https://github.com/KSPP/linux/issues/176 [6] https://codesearch.debian.net/search?q=execve%5C+*%5C%28%5B%5E%2C%5D%2B%2C+*NULL&literal=0 [7] https://codesearch.debian.net/search?q=execlp%3F%5Cs*%5C%28%5B%5E%2C%5D%2B%2C%5Cs*NULL&literal=0 [8] https://lore.kernel.org/lkml/20220131144352.GE16385@xsang-OptiPlex-9020/
- Published
- Feb 26, 2025
- Updated
- Aug 5, 2026
- EPSS
- 0.3% · 21th percentile
- CWE
- CWE-476
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 22 / 40 · 5.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CNA vs NVD score
- NVD
- 5.5
- CNA · Linux
- 7.8
- 2.3 point gap
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernelbefore 4.9.317
- linux linux kernel4.10 and later · before 4.14.282
- linux linux kernel4.15 and later · before 4.19.246
- linux linux kernel4.20 and later · before 5.4.197
- linux linux kernel5.5 and later · before 5.10.110
- linux linux kernel5.11 and later · before 5.15.33
- linux linux kernel5.16 and later · before 5.16.19
- linux linux kernel5.17 and later · before 5.17.2
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 2.6.12affected
- 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 41f6ea5b9aaa28b740d47ffe995a5013211fdbb0affected · git
- 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 98e0c7c702894987732776736c99b85ade6fba45affected · git
- 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before b50fb8dbc8b81aaa126387de428f4c42a7c72a73affected · git
- 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 1fe82bfd9e4ce93399d815ca458b58505191c3e8affected · git
- 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 27a6f495b63a1804cc71be45911065db7757a98caffected · git
- 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before 1290eb4412aa0f0e9f3434b406dc8e255da85f9eaffected · git
- 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before a8054d3fa5deb84b215d6be1b910a978f3cb840daffected · git
- 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before cfbfff8ce5e3d674947581f1eb9af0a1b1807950affected · git
- 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 and later · before dcd46d897adb70d63e025f175a00a89797d31a43affected · git
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 5.17.3-1 | 5.17.3-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
- CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV83Now
- CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV77This week
- CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV77This week
- CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV77This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 1290eb4412aa0f0e9f3434b406dc8e255da85f9e | Vendor (CNA) |
| Linux Linux | 1fe82bfd9e4ce93399d815ca458b58505191c3e8 | Vendor (CNA) |
| Linux Linux | 27a6f495b63a1804cc71be45911065db7757a98c | Vendor (CNA) |
| Linux Linux | 41f6ea5b9aaa28b740d47ffe995a5013211fdbb0 | Vendor (CNA) |
| Linux Linux | 98e0c7c702894987732776736c99b85ade6fba45 | Vendor (CNA) |
| Linux Linux | a8054d3fa5deb84b215d6be1b910a978f3cb840d | Vendor (CNA) |
| Linux Linux | b50fb8dbc8b81aaa126387de428f4c42a7c72a73 | Vendor (CNA) |
| Linux Linux | cfbfff8ce5e3d674947581f1eb9af0a1b1807950 | Vendor (CNA) |
| Linux Linux | dcd46d897adb70d63e025f175a00a89797d31a43 | Vendor (CNA) |
| debian:linux | 5.17.3-1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-476 · NULL Pointer DereferenceCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/1290eb4412aa0f0e9f3434b406dc8e255da85f9e
- git.kernel.org/stable/c/1fe82bfd9e4ce93399d815ca458b58505191c3e8
- git.kernel.org/stable/c/27a6f495b63a1804cc71be45911065db7757a98c
- git.kernel.org/stable/c/41f6ea5b9aaa28b740d47ffe995a5013211fdbb0
- git.kernel.org/stable/c/98e0c7c702894987732776736c99b85ade6fba45
- git.kernel.org/stable/c/a8054d3fa5deb84b215d6be1b910a978f3cb840d
- git.kernel.org/stable/c/b50fb8dbc8b81aaa126387de428f4c42a7c72a73
- git.kernel.org/stable/c/cfbfff8ce5e3d674947581f1eb9af0a1b1807950
- git.kernel.org/stable/c/dcd46d897adb70d63e025f175a00a89797d31a43
Vendor advisories and official records. Exploit/PoC links are deliberately left out.